$ 660,206

^[1]

$ 560,041

^[1]

$ 479,741

^[1]

Cost of revenues

162,100

143,653

118,458

General and administrative

498,106

416,388

361,283

Operating expenses:

Sales and marketing

180,046

152,041

142,174

112,752

99,295

91,595

Research and development

44,083

42,869

37,154

Impairment of goodwill

40,693

36,591

Impairment of long lived assets

26,320

Total operating expenses

403,894

330,796

270,923

Income from operations

94,212

85,592

90,360

Other income (expense), net

(1,073)

(1,296)

(419)

Net income before provision for income taxes

93,139

84,296

89,941

Provision for income taxes

28,844

25,605

23,225

Net income

$ 64,295

$ 58,691

$ 66,716

Net income per share:

Basic (usd per share)

$ 0.80

$ 0.73

$ 0.86

Diluted (usd per share)

$ 0.78

$ 0.71

$ 0.83

Shares used in computing net income per share:

Basic (shares)

80,551

80,529

77,988

Diluted (shares)

82,589

83,040

80,294

[1]	Net revenues are attributed to countries based on location of where revenue is recognized.2 Long-lived assets are attributed to countries based on entity that owns the assets.

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Net income	$ 64,295	$ 58,691	$ 66,716
Net change in cumulative translation adjustment	62	129	10
Change in unrealized gains (losses) on available-for sale securities, net of tax	29	28	(98)
Other comprehensive income (loss)	91	157	(88)
Comprehensive income (loss)	$ 64,386	$ 58,848	$ 66,628

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 20

-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Other Comprehensive Income

-URI http://asc.fasb.org/extlink&oid=6519514

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Net Income

-URI http://asc.fasb.org/extlink&oid=6518256

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.19)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.18)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.22)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e565-108580

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 19

-Article 5

+ Details

Summary of Significant Accounting Policies

Amount after tax, before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

+ References+ Details

CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 242,953	$ 306,386
Marketable securities, short-term	127,040	28,485
Accounts receivable, net of allowance for doubtful accounts and returns of $1,733 and $3,167, respectively	113,250	98,992
Inventories	13,968	15,122
Prepaid expenses and other current assets	47,465	36,808
Total current assets	544,676	485,793
Marketable securities, long-term	101,978	21,252
Property, plant and equipment, net	75,743	79,191
Goodwill	61,623	99,236
Intangible assets, net	23,739	45,777
Deferred tax assets	15,766	21,609
Other assets	8,622	3,454
Total assets	832,147	756,312
Current liabilities:
Accounts payable	17,718	19,549
Accrued liabilities	80,345	74,247
Deferred revenues	77,275	61,975
Total current liabilities	175,338	155,771
Other long-term liabilities	22,839	19,224
Total liabilities	198,177	174,995
Commitments and contingencies (Notes 7 and 9)
Stockholders' equity:
Preferred stock, $0.0001 par value (5,000 shares authorized; none issued)	0	0
Common stock, $0.0001 par value (200,000 shares authorized; 80,583 and 80,611 issued and outstanding at 2013 and 2012, respectively)	8	8
Additional paid-in capital	729,578	670,732
Accumulated other comprehensive income, net	294	203
Accumulated deficit	(95,910)	(89,626)
Total stockholders' equity	633,970	581,317
Total liabilities and stockholders' equity	$ 832,147	$ 756,312

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts and returns	$ 1,733	$ 3,167
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (shares)	5,000	5,000
Preferred stock, issued (shares)
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (shares)	200,000	200,000
Common stock, issued (shares)	80,583	80,611
Common stock, outstanding (shares)	80,583	80,611

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2010
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 66,716				$ 66,716
Net change in unrealized gain (loss) from available-for sale securities	10			10
Net change in cumulative translation adjustment	(98)			(98)
Issuance of common stock relating to employee equity compensation plans (in shares)		2,708
Issuance of common stock relating to employee equity compensation plans	25,501	0	25,501
Tax withholdings related to net share settlements of restricted stock units	(1,897)		(1,897)
Shares issued for litigation settlement (shares)		(322)
Stock Issued During Period, Value, Other	(7,754)		(2,771)		(4,983)
Excess tax benefit from share based payment arrangements	11,391		11,391
Stock based compensation	19,165		19,165
Ending Balance at Dec. 31, 2011	490,781	8	607,240	46	(116,513)
Ending Balance (in shares) at Dec. 31, 2011		78,776
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	58,691				58,691
Net change in unrealized gain (loss) from available-for sale securities	28			28
Net change in cumulative translation adjustment	129			129
Issuance of common stock relating to employee equity compensation plans (in shares)		3,565
Issuance of common stock relating to employee equity compensation plans	42,327	0	42,327
Tax withholdings related to net share settlements of restricted stock units	(2,106)		(2,106)
Common stock repurchased and retired (shares)		1,730
Common stock repurchased and retired	47,203		15,399		31,804
Excess tax benefit from share based payment arrangements	17,187		17,187
Stock based compensation	21,483		21,483
Ending Balance at Dec. 31, 2012	581,317	8	670,732	203	(89,626)
Ending Balance (in shares) at Dec. 31, 2012		80,611
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	64,295				64,295
Net change in unrealized gain (loss) from available-for sale securities	29			29
Net change in cumulative translation adjustment	62			62
Issuance of common stock relating to employee equity compensation plans (in shares)		2,694
Issuance of common stock relating to employee equity compensation plans	34,196		34,196
Tax withholdings related to net share settlements of restricted stock units	(4,363)		(4,363)
Common stock repurchased and retired (shares)		2,722
Common stock repurchased and retired	95,107		24,528		70,579
Excess tax benefit from share based payment arrangements	27,103		27,103
Stock based compensation	26,438		26,438
Ending Balance at Dec. 31, 2013	$ 633,970	$ 8	$ 729,578	$ 294	$ (95,910)
Ending Balance (in shares) at Dec. 31, 2013		80,583

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 64,295	$ 58,691	$ 66,716
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred taxes	21,204	17,783	5,842
Depreciation and amortization	13,887	13,440	12,112
Stock-based compensation	26,438	21,483	19,165
Amortization of intangibles	2,938	4,371	5,365
Excess tax benefit from share-based payment arrangements	(27,103)	(17,187)	(11,391)
Impairment of goodwill	40,693	36,591	0
Impairment of long-lived assets	26,320	0	0
Other	4,142	4,517	2,572
Changes in assets and liabilities, excluding the effects of business combinations:
Accounts receivable	(11,981)	(11,666)	(24,147)
Inventories	1,158	(5,718)	(4,058)
Prepaid expenses and other assets	(392)	(3,853)	(2,681)
Accounts payable	(186)	(6)	7,535
Accrued and other long-term liabilities	9,662	2,943	37,105
Deferred revenues	14,901	12,389	16,334
Net cash provided by operating activities	185,976	133,778	130,469
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition, net of cash acquired	(7,652)	0	(187,588)
Purchase of property, plant and equipment	(19,412)	(38,333)	(30,404)
Purchase of marketable securities	(303,917)	(67,511)	0
Proceeds from maturities of marketable securities	90,917	24,901	8,915
Proceeds from Sale and Maturity of Marketable Securities	31,741	297	1,402
Other assets	(2,411)	2,346	(3,931)
Net cash used in investing activities	(210,734)	(78,300)	(211,606)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	34,196	42,327	25,501
Common stock repurchase	(95,107)	(47,203)	(7,754)
Excess tax benefit from share-based payment arrangements	27,103	17,187	11,391
Employees' taxes paid upon the vesting of restricted stock units	(4,363)	(2,106)	(1,897)
Net cash (used in) provided by financing activities	(38,171)	10,205	27,241
Effect of foreign exchange rate changes on cash and cash equivalents	(504)	28	(93)
Net (decrease) increase in cash and cash equivalents	(63,433)	65,711	(53,989)
Cash and cash equivalents, beginning of year	306,386	240,675	294,664
Cash and cash equivalents, end of year	$ 242,953	$ 306,386	$ 240,675

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2013

Accounting Policies [Abstract]

Business Description

Align Technology, Inc. (“We”, “Our”, or “Align”) was incorporated in April 1997 in Delaware and focuses on designing, manufacturing and marketing innovative, technology-rich products to help dental professionals achieve the clinical results they expect and deliver effective, convenient cutting-edge dental treatment options to their patients. We are headquartered in San Jose, California with offices worldwide. Our international headquarters are located in Amsterdam, the Netherlands. We have two operating segments, (1) Clear Aligner, known as the Invisalign System, and (2) Scanners and CAD/CAM Services ("SCCS"), known as the iTero intra-oral scanner and OrthoCAD services.

Basis of presentation and preparation

The consolidated financial statements include the accounts of Align and our wholly-owned subsidiaries after elimination of intercompany transactions and balances. Certain amounts within revenues and cost of revenues in prior periods have been reclassified to conform with the current period presentation. These reclassifications had no impact on previously reported gross profit or financial position.

In connection with the preparation of the consolidated financial statements, we evaluated events subsequent to the balance sheet date through the financial statement issuance date and determined that all material transactions have been recorded and disclosed properly.

Out of period adjustment

In 2013, we recorded an out of period correction that resulted in decreases in cost of net revenues of approximately $1.7 million and operating expense of $0.7 million offset in part by an increase in the provision for income taxes of $0.5 million. We do not believe the increase of $1.9 million to net income related to the out of period adjustment is material to the consolidated financial statements for the fiscal year ended December 31, 2013 or to any prior years' consolidated financial statements.

Use of estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S.”) requires our management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates. On an ongoing basis, we evaluate our estimates, including those related to the fair values of financial instruments, intangible assets and goodwill, useful lives of intangible assets and property and equipment, stock-based compensation, revenue recognition, income taxes, and contingent liabilities, among others. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities.

Fair value of financial instruments

The carrying amounts of our cash, accounts receivable, accounts payable and other current liabilities approximate their fair value.

We measure our cash equivalents, marketable securities, and our Israeli severance fund at fair value. Fair value is the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:

Level 1— Quoted (unadjusted) prices in active markets for identical assets or liabilities.

Level 2— Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability.

Level 3 – Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability.

Cash and cash equivalents

We consider currency on hand, demand deposits, time deposits, and all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash and cash equivalents. Cash and cash equivalents are held in various financial institutions in the U.S. and internationally.

Restricted cash

Our restricted cash balance as of December 31, 2013 was $4.0 million, included in Long Term Assets, and primarily consisted of funds reserved for legal requirements. The restricted cash balance as of December 31, 2012 was $1.6 million, included in Prepaid Expenses and Other Current Assets, and represented unclaimed merger consideration related to the acquisition of Cadent Holdings in April 2011.

Marketable securities

We invest primarily in money market funds, commercial paper, corporate bonds, U.S. dollar dominated foreign corporate bonds, U.S. government agencies and municipal bonds.

Marketable securities are classified as available-for-sale and are carried at fair value. Marketable securities classified as current assets have maturities of less than one year. Unrealized gains or losses on such securities are included in accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses from maturities of all such securities are reported in earnings and computed using the specific identification cost method. Realized gains or losses and charges for other-than-temporary declines in value, if any, on available-for-sale securities are reported in other income (expense) as incurred. We periodically evaluate these investments for other-than-temporary impairment.

Foreign currency

For our international subsidiaries where the U.S. dollar is the functional currency, we analyze on an annual basis or more often if necessary, if a significant change in facts and circumstances indicate that the primary economic currency has changed. Adjustments from translating certain European and Asia-Pacific subsidiaries’ financial statements from the local currency to the U.S. dollar are recorded as a separate component of accumulated other comprehensive income (loss), net in the stockholders’ equity section of the Consolidated Balance Sheets. This foreign currency translation adjustment reflects the translation of the balance sheet at period end exchange rates, and the income statement at an average exchange rate in effect during the period. As of December 31, 2013 and 2012, there were no material amounts in accumulated other comprehensive income, net related to the translation of our foreign subsidiaries’ financial statements.

Our other international entities operate in a U.S. dollar functional currency environment, and therefore, the foreign currency assets and liabilities are remeasured into the U.S. dollar at current exchange rates except for non-monetary assets and liabilities which are remeasured at historical exchange rates. Revenues and expenses are generally remeasured at an average exchange rate in effect during each period. Gains or losses from foreign currency remeasurement are included in other income (expense). For the year ended December 31, 2013 and 2012, foreign currency gains and losses were not significant.

Certain risks and uncertainties

Our operating results depend to a significant extent on our ability to market and develop our products. The life cycles of our products are difficult to estimate due, in part, to the effect of future product enhancements and competition. Our inability to successfully develop and market our products as a result of competition or other factors would have a material adverse effect on our business, financial condition and results of operations.

Our cash and investments are held primarily by two financial institutions. Financial instruments which potentially expose us to concentrations of credit risk consist primarily of cash equivalents, marketable securities and accounts receivable. We invest excess cash primarily in money market funds of major financial institutions, U.S. government agencies, U.S. dollar dominated foreign corporate bonds and domestic corporate bonds. If the carrying value of our investments exceeds the fair value, and the decline in fair value is deemed to be other-than-temporary, we will be required to write down the value of our investments, which could materially harm our results of operations and financial condition. Moreover, the performance of certain securities in our investment portfolio correlates with the credit condition of the U.S. economy. We provide credit to customers in the normal course of business. Collateral is not required for accounts receivable, but ongoing evaluations of customers’ credit worthiness are performed. We maintain reserves for potential credit losses and such losses have been within management’s expectations. No individual customer accounted for 10% or more of our accounts receivable at December 31, 2013 or 2012, or net revenues for the year ended December 31, 2013, 2012, or 2011.

In the U.S., the Food and Drug Administration (“FDA”) regulates the design, manufacture, distribution, pre-clinical and clinical study, clearance and approval of medical devices. Products developed by us may require approvals or clearances from the FDA or other international regulatory agencies prior to commercialized sales. There can be no assurance that our products will receive any of the required approvals or clearances. If we were denied approval or clearance or such approval was delayed, it may have a material adverse impact on us.

We have manufacturing operations located outside the U.S. We currently rely on our manufacturing facility in Costa Rica to prepare digital treatment plans using a sophisticated, internally developed computer-modeling program. In addition, we manufacture our clear aligners and distribute our intra-oral scanners at our facility in Juarez, Mexico, and we produce our handheld scanner wand in Or Yehuda, Israel. Our reliance on international operations exposes us to related risks and uncertainties, including difficulties in staffing and managing international operations such as hiring and retaining qualified personnel; controlling production volume and quality of manufacture; political, social and economic instability, particularly as a result of increased levels of violence in Juarez, Mexico and Israel; interruptions and limitations in telecommunication services; product and material transportation delays or disruption; trade restrictions and changes in tariffs; import and export license requirements and restrictions; fluctuations in foreign currency exchange rates; and potential adverse tax consequences. If any of these risks materialize, our international manufacturing operations, as well as our operating results, may be harmed.

We purchase certain inventory from sole suppliers. Additionally, we rely on a limited number of hardware manufacturers. The inability of any supplier or manufacturer to fulfill our supply requirements could materially and adversely impact our future operating results.

Inventories

Inventories are valued at the lower of cost or market, with cost computed using either standard cost (which approximates actual cost) or average and actual cost on a first-in-first-out basis. Excess and obsolete inventories are determined primarily based on future demand forecasts, and write-downs of excess and obsolete inventories are recorded as a component of cost of revenues.

Property, plant and equipment

Property, plant and equipment are stated at historical cost less accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets, generally three to ten years. We amortize leasehold improvements over the shorter of the remaining lease term of up to five years or the estimated useful lives of the assets. We depreciate buildings over periods up to 20 years. Land is not depreciated. Construction in progress is related to the construction or development of property (including land) and equipment that have not yet been placed in service for their intended use. Upon sale or retirement, the asset’s cost and related accumulated depreciation are removed from the general ledger and any related gains or losses are reflected in operating expenses. Maintenance and repairs are expensed as incurred.

Goodwill and finite-lived acquired intangible assets

Goodwill represents the excess of the purchase price paid over the fair value of tangible and identifiable intangible net assets acquired in business combinations and is allocated to the respective reporting units based on relative synergies generated.

Our intangible assets primarily consist of intangible assets acquired as part of the Cadent acquisition. These assets are amortized using the straight-line method over their estimated useful lives of one to fifteen years, reflecting the period in which the economic benefits of the assets are expected to be realized.

Impairment of goodwill and long-lived assets

Goodwill

We evaluate goodwill for impairment at least annually on November 30th or more frequently if indicators are present, an event occurs or circumstances changes that suggest an impairment may exist and that it would more likely than not reduce the fair value of a reporting unit below its carrying amount. The allocation of goodwill to the respective reporting unit is based on relative synergies generated as a result of an acquisition.

We perform an initial assessment of qualitative factors to determine whether the existence of events and circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. In performing the qualitative assessment, we identify and consider the significance of relevant key factors, events, and circumstances that affect the fair value of our reporting units. These factors include external factors such as macroeconomic, industry, and market conditions, as well as entity-specific factors, such as our actual and planned financial performance. We also give consideration to the difference between the reporting unit fair value and carrying value as of the most recent date a fair value measurement was performed. If, after assessing the totality of relevant events and circumstances, we determine that it is more likely than not that the fair value of the reporting unit exceeds its carrying value and there is no indication of impairment, no further testing is performed; however, if we conclude otherwise, the first step of the two-step impairment test is performed by estimating the fair value of the reporting unit and comparing it with its carrying value, including goodwill.

Step one of the goodwill impairment test consists of a comparison of the fair value of a reporting unit against its carrying amount, including the goodwill allocated to each reporting unit. We determine the fair value of our reporting units based on the present value of estimated future cash flows under the income approach of the reporting units as well as various price or market multiples applied to the reporting unit's operating results along with the appropriate control premium under the marketing approach, both of which are classified as level 3 within the fair value hierarchy (as described in Note 2 in our consolidated financial statements). If the carrying amount of the reporting unit is in excess of its fair value, step two requires the comparison of the implied fair value of the reporting unit’s goodwill against the carrying amount of the reporting unit’s goodwill. Any excess of the carrying value of the reporting unit’s goodwill over the implied fair value of the reporting unit’s goodwill is recorded as an impairment loss.

The remaining goodwill is entirely attributable to our Clear Aligner reporting unit. During the fourth quarter of fiscal 2013, we performed the annual goodwill impairment testing using the qualitative approach discussed above and found no impairment as the fair value of our Clear Aligner reporting unit was significantly in excess of the carrying value.

Finite-lived intangible assets and long-lived assets

We evaluate long-lived assets (including finite-lived intangible assets) for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. An asset or asset group is considered impaired if its carrying amount exceeds the future undiscounted net cash flows the asset or asset group is expected to generate. If an asset or asset group is considered to be impaired, the impairment to be recognized is calculated as the amount by which the carrying amount of the asset or asset group exceeds its fair market value. Our estimates of future cash flows attributable to our long-lived assets require significant judgment based on our historical and anticipated results and are subject to many factors. Factors we consider important which could trigger an impairment review include significant negative industry or economic trends, significant loss of customers and changes in the competitive environment. We use a DCF approach, utilizing harvest model, to estimate the fair value of a reporting unit, which we believe is the most reliable indicator of fair value of a business, and is most consistent with the approach of a marketplace participant would use. The estimation of fair value utilizing a DCF approach includes numerous uncertainties which require our significant judgment when making assumptions of expected growth rates and the selection of discount rates, as well as assumptions regarding general economic and business conditions, and the structure that would yield the highest economic value, among other factors. Key assumptions used in measuring the fair values of SCCS reporting unit included the discount rate (based on the weighted-average cost of capital) and revenue growth. The fair value of SCCS’s trademark was determined using a risk-adjusted DCF model under the relief-from-royalty method. The royalty rate used was based on a consideration of market rates. The fair value of SCCS’s finite-lived customer relationships was determined using a DCF model under the multi-period excess earnings method. We recorded a long-lived asset impairment in the quarter ended March 31, 2013 due to changes in the competitive environment for our intra-oral scanners, including announcements from our competitors of new low-priced scanners targeted at orthodontists and general practitioner dentists in North America. There was no triggering event related to the Clear Aligner asset group. Refer to Note 5 for details of the impairment analysis.

There were no further triggering events in 2013 that would cause further impairments of our long-lived assets.

Development costs for internal use software

Costs relating to internal use software are accounted for in accordance with the provisions of accounting for the costs of computer software developed or obtained for internal use. Capitalized software costs are amortized over the estimated useful life of three years. Development costs for internal use software for the year ended December 31, 2013, 2012, or 2011 were not material.

Product Warranty

Clear Aligner

We warrant our Invisalign products against material defects until the Invisalign case is complete. We accrue for warranty costs in cost of net revenues upon shipment of products. The amount of accrued estimated warranty costs is primarily based on historical experience as to product failures as well as current information on replacement costs. Actual warranty costs could differ materially from the estimated amounts. We regularly review the accrued balances and update these balances based on historical warranty cost trends. As a result of our mid-course correction policy change in June 2013, we Have experienced a reduction in our warranty claims, which has decreased our warranty reserve.

Scanners and CAD/CAM Services

We warrant our intra-oral scanners for a period of one year, which include materials and labor. We accrue for these warranty costs based on average historical repair costs. An extended warranty may be purchased for additional fees.

Allowance for Doubtful Accounts and Returns

We maintain allowances for doubtful accounts, for customers that are not able to make payments, and for sales returns. We periodically review these allowances, including an analysis of the customers’ payment history and information regarding the customers’ creditworthiness, as well as historical sales returns as a percentage of revenue. Actual write-offs have not materially differed from the estimated allowance.

Revenue Recognition

We measure and allocate revenue according to the accounting guidance for multiple-deliverable revenue arrangements in Accounting Standards Update (“ASU”) 2009-13, Multiple-Deliverable Revenue Arrangements-a consensus of the Financial Accounting Standard Board (“FASB” )Emerging Issues Task Force.

Multiple-Element Arrangements (“MEAs”): Arrangements with customers may include multiple deliverables, including any combination of products/equipment and services. The deliverables included in the MEAs are separated into more than one unit of accounting when (i) the delivered product/equipment has value to the customer on a stand-alone basis, and (ii) delivery of the undelivered service element(s) is probable and substantially in our control. Arrangement consideration is then allocated to each unit, delivered or undelivered, based on the relative selling price (“RSP”) of each unit of accounting based first on vendor-specific objective evidence (“VSOE”) if it exists, second on third-party evidence (“TPE”) if it exists, and on best estimated selling price (“BESP”) if neither VSOE or TPE exist.

•

VSOE – In most instances, products are sold separately in stand-alone arrangements. Services are also sold separately through renewals of contracts with varying periods. We determine VSOE based on its pricing and discounting practices for the specific product or service when sold separately, considering geographical, customer, and other economic or marketing variables, as well as renewal rates or stand-alone prices for the service element(s).


•	TPE – If we cannot establish VSOE of selling price for a specific product or service included in a multiple-element arrangement, we use third-party evidence of selling price. We determine TPE based on sales of comparable amount of similar products or service offered by multiple third parties considering the degree of customization and similarity of product or service sold.

•

BESP – The best estimated selling price represents the price at which we would sell a product or service if it were sold on a stand-alone basis. When VSOE or TPE do not exist for all elements, we determine BESP for the arrangement element based on sales, cost and margin analysis, as well as other inputs based on its pricing practices. Adjustments for other market and Company-specific factors are made as deemed necessary in determining BESP.

Provisions for discounts and rebates to customers are provided for in the same period that the related product sales are recorded based upon historical discounts and rebates.

Clear Aligner

We enter into arrangements (“treatment plans”) that involve multiple future product deliverables. Invisalign Full, Invisalign Teen and Invisalign Assist include up to 3 optional case refinements. Case refinement is a finishing tool used to adjust a patient's teeth to the desired final position. Case refinement may be elected by the dental professional at any time during treatment however it is generally ordered in the last stages of orthodontic treatment. Beginning June 15, 2013, Invisalign Full and Invisalign Teen also include up to three optional mid-course corrections. Mid-course correction is a treatment adjustment during active treatment if the case is not tracking to the original treatment plan or goals. Mid-course correction gives doctors the ability to "adjust course' based on the needs of the individual patient. Invisalign Teen also includes up to six optional replacement aligners in the price of the product and may be ordered any time throughout treatment.

We determined that our treatment plans, except Invisalign Assist with progress tracking, comprise the following deliverables which also represent separate units of accounting: single-batched aligners, case refinement mid-course correction and replacement aligners. We allocate revenue for each treatment plan based on each unit's relative selling price based on BESP and recognize the revenue upon the delivery of each unit in the treatment plan. We regularly review our estimates of selling price and maintain internal controls over the establishment and update of these estimates.

For Invisalign Assist with the progress tracking feature, aligners and services are provided to the dental professional every nine stages (“a batch”). Beginning January 1, 2011, we were able to reliably estimate the number of batches which are expected to be shipped for each case based upon our historical experience. The amounts allocated to this deliverable are recognized on a prorated basis as each batch is shipped.

Prior to 2013, the Vivera Retainer included four shipments per year, and revenue was recognized ratably as each shipment occurred. In the first quarter of 2013, we consolidated Vivera Retainer product shipments down to one shipment per year.

Scanners and CAD/CAM Services

We recognize revenues from the sales of iTero intra-oral scanners and CAD/CAM services. CAD/CAM services include scanning services, extended warranty for the intra-oral scanners, a range of iTero restorative services and OrthoCAD services such as OrthoCAD iRecord. We sell intra-oral scanners and services through both our direct sales force and distribution partners. The intra-oral scanner sales price includes one year of warranty, and for additional fees, the customer may select an unlimited scanning service agreement over a fixed period of time or extended warranty periods. Revenue is recognized when persuasive evidence of the arrangement exists, the price is fixed or determinable, collectability is reasonably assured, title and risk of loss has passed to customers based on the shipping terms, no significant obligations remain, and allowances for discounts, returns, and customer incentives can be reliably estimated. When intra-oral scanners are sold with either an unlimited scanning service agreement and/or extended warranty, we allocate revenue based on each element's relative selling price. We estimate the selling price of each element, as if it is sold on a stand-alone basis, taking into consideration historical prices as well as our discounting strategies. Scanner revenue, net of related discounts and allowances, is recognized when products or equipment have been shipped, installed and on-site training completed. For certain distributors who provide installation and training to the customer, we recognize scanner revenue when the intra-oral scanner is shipped to the distributor assuming all of the other revenue recognition criteria have been met.

Discounts are deducted from revenue at the time of sale or when the discount is offered, whichever is later and free cases or training is included as a deliverable in the multiple-element arrangement assessment. Returns of products, excluding warranty related returns, are infrequent and insignificant.

Service revenue, including iTero restorative and all OrthoCAD services are recognized upon delivery or ratably over the contract term as the specified services are performed. If a customer selects a pay per use basis for scanning service fees, the revenue is recognized as the service is provided.

We offer customers an option to purchase extended warranties on certain products. We recognize revenue on these extended warranty contracts ratably over the life of the contract. The costs associated with these extended warranty contracts are recognized when incurred.

Shipping and Handling Costs

Shipping and handling charges to customers are included in net revenues, and the associated costs incurred are recorded in cost of revenues.

Legal Proceedings and Litigations

We are involved in legal proceedings on an ongoing basis. If we believe that a loss arising from such matters is probable and can be reasonably estimated, we accrue the estimated liability in our financial statements. If only a range of estimated losses can be determined, we accrue an amount within the range that, in our judgment, reflect the most likely outcome; if none of the estimates within that range is a better estimate than any other amount, we accrue the low end of the range.

Research and development

Research and development expense is expensed as incurred and includes the costs associated with the research and development of new products and enhancements to existing products. These costs primarily include compensation costs, including stock-based compensation expense, outside consulting expenses , costs associated with conducting clinical and pre-commercialization trial and testing, allocations of corporate overhead expenses including facilities, IT and human resource costs, equipment costs and depreciation and amortization.

Advertising costs

The cost of advertising and media is expensed as incurred. For the years ended December 31, 2013, 2012 and 2011 advertising costs totaled $26.0 million, $23.6 million and $21.2 million, respectively.

Common stock repurchase

We repurchase our own common stock from time to time in the open market when our Board of Directors approve a stock repurchase program. We account for these repurchase under the accounting guidance for equity where we allocate the total repurchase value that are in excess over par between additional paid in capital and retained earnings. All shares repurchased are retired.

Operating leases

We currently lease office spaces, automobiles and equipment under operating leases with original lease periods of up to 9 years. Certain of these leases have free or escalating rent payment provisions and lease incentives provided by the landlord. We recognize rent expense under such leases on a straight-line basis over the term of the lease as certain leases have adjustments for market provisions.

Income taxes

We make certain estimates and judgments in determining income tax expense for financial statement purposes. These estimates and judgments occur in the calculation of certain tax assets and liabilities, which arise from differences in the timing of recognition of revenue and expense for tax and financial statement purposes.

As part of the process of preparing our Consolidated Financial Statements, we are required to estimate our income taxes in each of the jurisdictions in which we operate. This process involves us estimating our current tax exposure under the applicable tax laws and assessing temporary differences resulting from differing treatment of items for tax and accounting purposes. These differences result in deferred tax assets and liabilities, which are included in our Consolidated Balance Sheets.

We account for uncertainty in income taxes pursuant to authoritative guidance based on a two-step approach to recognize and measure uncertain tax positions taken or expected to be taken in a tax return. The first step is to determine if the weight of available evidence indicates that it is more likely than not that the tax position will be sustained on audit based on its technical merits, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. We adjust reserves for our uncertain tax positions due to changing facts and circumstances, such as the closing of a tax audit, or refinement of estimates due to new information. To the extent that the final outcome of these matters is different than the amounts recorded, such differences will impact our tax provision in our Consolidated Statements of Operations in the period in which such determination is made.

We assess the likelihood that we will be able to realize our deferred tax assets. Should there be a change in our ability to realize our deferred tax assets, our tax provision would increase in the period in which we determine that it is more likely than not that we cannot realize our deferred tax assets. We consider all available evidence, both positive and negative, including historical levels of income, expectations and risks associated with estimates of future taxable income and ongoing prudent and feasible tax planning strategies in assessing the need for a valuation allowance. If it is more likely than not that we will not realize our deferred tax assets, we will increase our provision for taxes by recording a valuation allowance against the deferred tax assets that we estimate will not ultimately be realizable. The available positive evidence at December 31, 2013 included historical operating profits and a projection of future income sufficient to realize most of our remaining deferred tax assets. As of December 31, 2013, it was considered more likely than not that our deferred tax assets would be realized with the exception of certain foreign loss carryovers as we are unable to forecast sufficient future profits to realize the deferred tax assets.

As of December 31, 2013, U.S. income taxes and foreign withholding taxes associated with the repatriation of undistributed earnings of foreign subsidiaries were not provided for on a cumulative total of $186.4 million. We intend to reinvest these earnings indefinitely in our foreign subsidiaries. If these earnings were distributed in the form of dividends or otherwise, or if the shares of the relevant foreign subsidiaries were sold or otherwise transferred, we would be subject to additional U.S. income taxes subject to an adjustment for foreign tax credit, and foreign withholding taxes. Determination of the amount of unrecognized deferred income tax liability related to these earnings is not practicable.

Accounting guidance for stock-based compensation prohibits recognition of a deferred income tax asset for excess tax benefits due to stock option exercises that have not yet been realized through a reduction in income taxes payable. We follow the tax law ordering method to determine when excess tax benefits have been realized and consider only the direct impacts of awards when calculating the amount of windfalls or shortfalls.

Stock-based compensation

We recognize stock-based compensation cost for only those shares ultimately expected to vest on a straight-line basis over the requisite service period of the award. We estimate the fair value of market-performance based restricted stock units using a Monte Carlo simulation model which requires the input of assumptions, including expected term, stock price volatility and the risk-free rate of return. In addition, judgment is also required in estimating the number of stock-based awards that are expected to be forfeited. Forfeitures are estimated based on historical experience at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The assumptions used in calculating the fair value of share-based payment awards represent management’s best estimates, but these estimates involve inherent uncertainties and the application of management’s judgment. As a result, if factors change and we use different assumptions, our stock-based compensation expense could be materially different in the future.

Medical Device Excise Taxes

In accordance with the Patient Protection and Affordable Care Act, effective January 1, 2013, we began to incur an excise tax on sales of medical devices in the U.S. We record the medical device excise tax in general and administrative expenses in the consolidated statement of operations. The medical excise tax expense was $7.1 million for the year ended December 31, 2013. Any future changes in the applicability of the medical device excise tax as it applies to us will be recorded as an additional expense or a credit to the consolidated statement of operations in the period in which it becomes probable and reasonably estimable.

Comprehensive income (loss)

Comprehensive income (loss) includes all changes in equity during a period from non-owner sources. Comprehensive income (loss), including unrealized gains and losses on available-for-sale securities and foreign currency translation adjustments, are reported net of their related tax effect.

Recent Accounting Pronouncements

In July 2013, Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2013-11, "Presentation of an Unrecognized Tax Benefit when a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force)." The amendments in this ASU provide guidance on the financial statements presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. An unrecognized tax benefit should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward with certain exceptions, in which case such an unrecognized tax benefit should be presented in the financial statements as a liability. The amendments in this ASU do not require new recurring disclosures and are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. We are currently assessing the impact of this ASU on our consolidated financial statements.

Investments, All Other Investments [Abstract]

The entire disclosure for all significant accounting policies of the reporting entity.

+ References+ Details

Marketable Securities and Fair Value Measurements

12 Months Ended

Dec. 31, 2013

Marketable Securities and Fair Value Measurements

As of December 31, 2013 and 2012, the estimated fair value of our short-term and long-term investments, classified as available for sale, are as follows (in thousands):

Short-term



December 31, 2013	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	54,318	$	10	$	—		$	54,328
Corporate bonds	29,079		10		(4		)	29,085
U.S. dollar dominated foreign corporate bonds	13,959		12		—			13,971
Municipal securities	7,006		11		(3		)	7,014
U.S. government agency bonds	16,693		10		—			16,703
Asset-backed securities	5,937		2		—			5,939
Total Marketable Securities, Short-Term	$	126,992	$	55	$	(7	)	$	127,040

Long-term



December 31, 2013	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	38,138	$	1	$	(21	)	$	38,118
Corporate bonds	23,308		14		(9		)	23,313
U.S. dollar dominated foreign corporate bonds	19,485		27		(17		)	19,495
U.S. government treasury bonds	6,916		3		—			6,919
Municipal securities	8,326		13		(8		)	8,331
Asset-backed securities	5,800		4		(2		)	5,802
Total Marketable Securities, Long-Term	$	101,973	$	62	$	(57	)	$	101,978

Short-term



December 31, 2012	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	4,646	$	1	$	—		$	4,647
Corporate bonds	18,767		7		(4		)	18,770
U.S. dollar dominated foreign corporate bonds	5,060		9		(1		)	5,068
Total Marketable Securities, Short-Term	$	28,473	$	17	$	(5	)	$	28,485

Long-term



December 31, 2012	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Corporate bonds	$	16,132	$	16	$	(7	)	$	16,141
U.S. dollar dominated foreign corporate bonds	3,038		4		(1		)	3,041
U.S. government agency bonds	2,069		1		—			2,070
Total Marketable Securities, Long-Term	$	21,239	$	21	$	(8	)	$	21,252

For the years ended December 31, 2013 and 2012, realized losses were immaterial. Cash and cash equivalents were not included in the table above as the gross unrealized gains and losses were not material. We have no material short-term or long-term investments that have been in continuous unrealized loss positions for greater than twelve months as of December 31, 2013. Amounts reclassified to earnings from unrealized gain or losses were immaterial in 2013 and 2012.

Our fixed-income securities investment portfolio consists of corporate bonds, U.S. dollar dominated foreign corporate bonds, commercial paper, municipal securities, U.S. government agency bonds and asset-backed securities that have a maximum maturity of two years. The securities that we invest in are generally deemed to be low risk based on their credit ratings from the major rating agencies. The longer the duration of these securities, the more susceptible they are to changes in market interest rates and bond yields. As interest rates increase, those securities purchased at a lower yield show a mark-to-market unrealized loss. The unrealized losses are due primarily to changes in credit spreads and interest rates. We expect to realize the full value of all these investments upon maturity or sale. The weighted average remaining duration of these securities was approximately 10 months as of December 31, 2013 and 2012.

As the carrying value approximates the fair value for our short-term and long-term marketable securities shown in the tables above, the following table summarizes the fair value of our short-term and long-term marketable securities classified by maturity as of December 31, 2013 and 2012 (in thousands):



	December 31,		December 31,
	2013		2012
One year or less	$	127,040	$	28,485
One year through two years	101,978		21,252
	$	229,018	$	49,737

Fair Value Measurements

We measure the fair value of our cash equivalents and marketable securities as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. We use the U.S. GAAP fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. This hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs that may be used to measure fair value:

Level 1—Quoted (unadjusted) prices in active markets for identical assets or liabilities.

Our Level 1 assets consist of money market funds and commercial paper. We did not hold any Level 1 liabilities as of December 31, 2013 or 2012.

Level 2—Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability.

Our Level 2 assets consist of commercial paper, corporate bonds, U.S. dollar denominated foreign corporate bonds, U.S. government agency bonds, and our Israeli funds that are mainly invested in insurance policies. We obtain these fair values for level 2 investments from our asset manager for each of our portfolios. Our custody bank and asset managers independently use professional pricing services to gather pricing data which may include quoted market prices for identical or comparable financial instruments, or inputs other than quoted prices that are observable either directly or indirectly, and we are ultimately responsible for these underlying estimates.

We did not hold any Level 2 liabilities as of December 31, 2013 or 2012.

Level 3—Unobservable inputs to the valuation methodology that are supported by little or no market activity and that are significant to the measurement of the fair value of the assets or liabilities. Level 3 assets and liabilities include those whose fair value measurements are determined using pricing models, discounted cash flow ("DCF") methodologies or similar valuation techniques, as well as significant management judgment or estimation.

We did not hold any Level 3 assets or liabilities as of December 31, 2013 or 2012.

Non-Recurring Fair Value Measurements

During 2013, we recorded an impairment charge to our long-lived assets and goodwill of $26.3 million and $40.7 million, respectively, related to our Scanner and CAD/CAM Services ("SCCS") reporting unit as an event occurred and circumstances changed that led us to perform an impairment analysis prior to our annual test which required us to determine the fair value of the SCCS reporting unit (Refer to Note 5). These fair value measurements were calculated using unobservable inputs, using the income approach which is classified as Level 3 within the fair value hierarchy. Inputs for the income approach includes the amount and timing of future cash flows based on our most recent operational budgets, strategic plans, terminal growth rates assumptions and other estimates.

During 2012, we recorded a goodwill impairment charge of $36.6 million related to our SCCS reporting unit as an event occurred or circumstances changed that led us to perform a goodwill impairment analysis between the annual test which required us to determine the fair value of the SCCS reporting unit (Refer to Note 5). These fair value measurements were calculated using unobservable inputs, using both the income and market approach, which are classified as Level 3 within the fair value hierarchy. Inputs for the income approach includes the amount and timing of future cash flows based on our most recent operational budgets, strategic plans, terminal growth rates assumptions and other estimates. The primary input for the market approach include market multiples for guideline companies that operate in a similar business environment.

The following table summarizes our financial assets measured at fair value on a recurring basis as of December 31, 2013and 2012 (in thousands):



Description	Balance as of December 31, 2013		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	143,540	$	143,540	$	—
Commercial paper	15,398		—		15,398
Short-term investments:
Commercial paper	54,328		—		54,328
Corporate bonds	29,085		—		29,085
U.S. dollar denominated foreign corporate bonds	13,971		—		13,971
Municipal securities	7,014		—		7,014
U.S. government agency bonds	16,703		—		16,704
Asset-backed securities	5,939		—		5,938
Long-term investments:
Corporate bonds	23,313		—		23,313
U.S. government agency bonds	38,118		—		38,118
U.S. dollar denominated foreign corporate bonds	19,495		—		19,495
U.S. government treasury bonds	6,919		6,919		—
Municipal securities	8,331		—		8,331
Asset-backed securities	5,802		—		5,802
Long-term other assets:
Israeli funds	2,193		—		2,193
	$	390,149	$	150,459	$	239,690



Description	Balance as of December 31, 2012		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	86,166	$	86,166	$	—
Commercial paper	950		—		950
Short-term investments:
Commercial paper	4,647		—		4,647
Corporate bonds	18,770		—		18,770
U.S. dollar denominated foreign corporate bonds	5,068		—		5,068
Long-term investments:
U.S. government agency bonds	2,070		—		2,070
Corporate bonds	16,141		—		16,141
U.S. dollar denominated foreign corporate bonds	3,041		—		3,041
Long-term other assets:
Israeli funds	2,218		—		2,218
	$	139,071	$	86,166	$	52,905

Balance Sheet Components

12 Months Ended

Dec. 31, 2013

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Components

Inventories

Inventories consist of the following (in thousands):



	December 31,
	2013		2012
Raw materials	$	5,172	$	7,629
Work in process	4,241		3,889
Finished goods	4,555		3,604
Total Inventories	$	13,968	$	15,122

Work in process includes costs to produce our clear aligner and intra-oral scanner products. Finished goods primarily represent our intra-oral scanners and ancillary products that support our clear aligner products.

Property, plant and equipment

Property, plant and equipment consist of the following (in thousands):



	December 31,
	2013			2012
Clinical and manufacturing equipment	$	104,373		$	83,821
Computer hardware	24,851			22,706
Computer software	21,286			20,346
Furniture and fixtures	7,275			6,808
Leasehold improvements	14,996			12,388
Building	1,868			1,868
Land	1,162			1,162
Construction in progress	5,438			16,027
Total	181,249			165,126
Less: Accumulated depreciation and amortization and impairment charges ¹	(105,506		)	(85,935		)
Total Property, plant and equipment, net	$	75,743		$	79,191

We recorded an impairment of our long-lived assets in 2013 which was a result of changes in the competitive environment for intra-oral scanners which included announcements of new low-priced scanners targeted at orthodontists and GPs in North America that caused us to lower our expectations for growth and profitability for our SCCS reporting unit. As a result, we determined that the carrying value of the long-lived assets was not recoverable and therefore recorded an impairment charge of $26.3 million, of which $7.0 million related to property and equipment. Refer to Note 5 for details of the impairment analysis.

As of December 31, 2013, construction in progress consisted primarily of costs for capital equipment to be placed in service in the next year. Depreciation and amortization was $13.9 million, $13.4 million, and $12.1 million, for the years ended December 31, 2013, 2012 and 2011, respectively.

Accrued liabilities

Accrued liabilities consist of the following (in thousands):



	December 31,
	2013		2012
Accrued payroll and benefits	$	43,029	$	39,621
Accrued sales rebate	10,100		8,333
Accrued sales tax and value added tax	6,215		5,253
Accrued sales and marketing expenses	3,893		4,088
Accrued warranty	3,104		4,050
Accrued accounts payable	2,764		2,866
Accrued professional fees	1,892		2,349
Accrued income taxes	1,205		572
Other accrued liabilities	8,143		7,115
Total Accrued Liabilities	$	80,345	$	74,247

Warranty

We regularly review the accrued balances and update these balances based on historical warranty trends. Actual warranty costs incurred have not materially differed from those accrued. However, future actual warranty costs could differ from the estimated amounts.

Clear Aligner

Scanners

We warrant our scanners for a period of one year from the date of training and installation. We accrue for these warranty costs which includes materials and labor based on estimated historical repair costs. Extended service packages may be purchased for additional fees.

Warranty accrual as of December 31, 2013 and 2012 consists of the following activity (in thousands):



Warranty accrual, December 31, 2011	$	3,177
Charged to cost of revenues	4,637
Actual warranty expenditures	(3,764		)
Warranty accrual, December 31, 2012	4,050
Charged to cost of revenues	2,850
Actual warranty expenditures	(3,796		)
Warranty accrual, December 31, 2013	$	3,104

Business Combinations

12 Months Ended

Dec. 31, 2013

Business Combinations [Abstract]

Business Combinations

Cadent

On April 29, 2011, we completed the acquisition of Cadent for an aggregate cash purchase price of approximately $187.6 million, acquiring all of Cadent's outstanding common and preferred stock. Cadent is a 3D digital scanning solution for orthodontics and dentistry. We believe that the combination of Align’s and Cadent’s technologies and capabilities creates greater growth opportunities for Align by bringing innovative new Invisalign treatment tools to customers and by extending the value of intra-oral scanning in dental practices.

The following table summarizes the allocation of the purchase price as of April 29, 2011 (in thousands):



Assets	$	15,745
Property, plant and equipment	3,624
Acquired identifiable intangible assets:
Trademarks (one to fifteen year useful lives)	7,100
Existing technology (thirteen year useful life)	12,600
Customer relationships (eleven year useful life)	33,500
Goodwill	135,349
Liabilities assumed	(20,330		)
Total	$	187,588

In 2011, we incurred direct transaction costs of approximately $6.4 million that include investment banking, legal and accounting fees, and other external costs directly related to the acquisition. These costs were expensed as incurred as part of our operating expenses.

Goodwill of $135.3 million represents the excess of the purchase price over the fair value of the underlying net tangible and identifiable intangible assets, and represents the expected synergies of the transaction and the knowledge and experience of the workforce in place. None of the goodwill is deductible for tax purposes. In connection with the acquisition, we allocated approximately $77.3 million of the goodwill from the Cadent acquisition to our Scanner and CAD/CAM Services ("SCCS") reporting unit and approximately $58.0 million to our Clear Aligner reporting unit based on the expected relative synergies generated by the acquisition. During the third quarter of 2012, we determined that goodwill for our SCCS reporting unit should be tested for impairment between annual impairment tests since an event occurred or circumstances changed that would more likely than not reduce the fair value of our SCCS reporting unit below its carrying amount. We recorded a total impairment charge of $36.6 million for the SCCS for 2012 after finalizing step two of our analysis. Further, during March 2013, changes in the competitive environment for intra-oral scanners, including announcements from our competitors of new low-priced scanners targeted at orthodontists and general practitioner dentists in North America, caused us to lower our expectations for growth and profitability for our SCCS reporting unit. As a result, we determined that goodwill related only to our SCCS reporting unit should be tested for impairment as of March 2013 due to these facts and circumstances which would more likely than not reduce the fair value of our SCCS reporting unit below its carrying amount. Based on our analysis, there was no implied goodwill for the SCCS reporting unit; therefore, we recorded a goodwill impairment charge of $40.7 million in the three months ended March 31, 2013, which represents the remaining goodwill balance in the SCCS reporting unit. All remaining goodwill from the Cadent acquisition as of December 31, 2013 is attributable to the Clear Aligner segment. See Note 5 for discussion of our goodwill impairment.

For the year ended December 31, 2013 and 2012, Cadent contributed net revenues of $45.6 million, $43.5 million, respectively, and gross profit of $13.3 million and $10.4 million respectively. During the period of May 2011 through December 2011, Cadent contributed net revenues of approximately $28.0 million and gross profit of approximately $6.5 million. Sales, marketing, development and administrative activities for our Clear Aligner and SCCS reporting units were integrated during the post-acquisition period, therefore the operating results below gross profit are not available.

The following table presents the results of Align and Cadent for the year ended December 31, 2011. The pro forma financial information is presented for informational purposes only and is not indicative of the results of operations that would have been achieved if the acquisition had taken place at the beginning of January 1, 2011 or results that may occur in the future (in thousands):



	Year Ended December 31,
	2011
Net revenues	$	492,468
Net income	$	62,116

ICA Holdings Pty Limited

On April 30, 2013, we completed the acquisition of ICA Holdings Pty Limited ("ICA") upon the expiration of the distribution agreement between certain subsidiaries of ICA and Align Technology B.V., for a total cash consideration of approximately $8.6 million, of which $7.4 million was attributed to assets acquired, $2.4 million in liabilities assumed and $3.6 million to goodwill. Goodwill as a result of this acquisition represents the excess of the purchase price over the fair value of the underlying net assets acquired and represents the knowledge and experience of the workforce in place. None of this goodwill will be deductible for tax purposes. Under the applicable accounting guidance, goodwill will not be amortized but will be tested for impairment on an annual basis or more frequently if certain indicators are present.

We believe that the transition from our distributor arrangement to a direct sales model as a result of the acquisition of ICA will increase our net revenues in the Asia Pacific region as we will experience higher average selling price(s) (“ASP”) as compared to our discounted ASP under the prior distribution agreement.

Pro forma results of operations for this acquisition have not been presented as it is not material to our results of operations, either individually or in aggregate, for the year ended December 31, 2013 or 2012 .

The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).

Goodwill and Intangible Assets Disclosure [Abstract]

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Goodwill and Intangible Assets

12 Months Ended

Dec. 31, 2013

Goodwill and Intangible Assets

Goodwill

The change in the carrying value of goodwill for the year ended December 31, 2013 by our reportable segments, which are also our reporting units, are as follows (in thousands):



	Clear Aligner			Scanners and CAD/CAM Services			Total
Balance as of December 31, 2011	$	58,445		$	76,938		$	135,383
Adjustment to goodwill ¹	98			346			444
Impairment of goodwill	—			(36,591		)	(36,591		)
Balance as of December 31, 2012	58,543			40,693			99,236
Goodwill from ICA acquisition	3,558			—			3,558
Impairment of goodwill	—			(40,693		)	(40,693		)
Adjustments ²	(478		)	—			(478		)
Balance as of December 31, 2013	$	61,623		$	—		$	61,623

Pursuant to the accounting guidance for business combinations, we recorded goodwill adjustments for the effect on goodwill of changes to net assets acquired related our acquisition of Cadent during the measurement period (up to one year from April 29, 2011, the date of our acquisition of Cadent). Goodwill adjustments were not significant to our previously reported operating results or financial position.


²	The adjustments to goodwill during 2013 were a result of foreign currency translation.

Impairment of Goodwill

2012 Impairment

During the third quarter of 2012, we determined that the goodwill for our SCCS reporting unit should be tested for impairment between annual impairment tests since an event occurred/circumstances changed that would more likely than not reduce the fair value of our SCCS reporting unit below its carrying amount. These indicators included the termination of an exclusive distribution arrangement with Straumann for iTero intra-oral scanners in Europe, as well as the termination of their non-exclusive distribution arrangement for iTero intra-oral scanners in North America, together with market conditions and business trends within the SCCS reporting unit. While we continued to expect revenue growth in our SCCS business, our expectations for future growth and profitability rates projected for the SCCS reporting unit were lower than our previous estimates primarily driven by overall lower than expected financial results.

As a result, we performed step one analysis for our SCCS reporting unit, which consists of a comparison of the fair value of the SCCS reporting unit against its carrying amount, including the goodwill allocated to it. In deriving the fair value of the SCCS reporting unit, we utilized a combination of both the income and market approach, which are classified as level 3 within the fair value hierarchy. The income approach provides an estimate of fair value based on discounted expected future cash flows. The market approach provides an estimate of fair value using various prices or market multiples applied to the reporting unit's operating results and then applies an appropriate control premium in order to reconcile to our market capitalization. As a result of our step one analysis, we concluded that the fair value of the SCCS reporting unit was less than its carrying value, therefore, we proceeded to perform step two of the goodwill impairment analysis.

Step two of the goodwill impairment analysis measures the impairment charge by allocating the reporting unit's fair value to all of the assets and liabilities of the reporting unit in a hypothetical analysis that calculates the implied fair value of goodwill in the same manner as if the reporting unit was being acquired in a business combination. This allocation process was performed only for the purposes of measuring the goodwill impairment, and not to adjust the carrying values of the recognized tangible assets and liabilities. Any excess of the carrying value of the reporting unit's goodwill over the implied fair value of the reporting unit's goodwill is recorded as an impairment loss. Based on our analysis, the implied fair value of goodwill was substantially lower than the carrying value of the goodwill for the SCCS reporting unit. We recorded a preliminary goodwill impairment charge during the third quarter of 2012 of $24.7 million and an additional $11.9 million during the fourth quarter of 2012, representing a change in estimate upon finalizing our 2013 annual budget process, for a total impairment charge of $36.6 million. None of the goodwill impairment charge was deductible for tax purposes.

2013 Impairment

We performed a step one analysis for our SCCS reporting unit which consists of a comparison of the fair value of the SCCS reporting unit against its carrying amount, including the goodwill allocated to it. In deriving the fair value of the SCCS reporting unit, we utilized the income approach which is classified as Level 3 within the fair value hierarchy. This approach provides an estimated fair value based on discounted expected future cash flows, which are based on management's estimates of revenue growth rates and operating margins, taking into consideration industry and market conditions. The discount rate used is based on a weighted average cost of capital adjusted for the relevant risk associated with the characteristics of the business and the projected cash flows.

As a result of our step one analysis, we concluded that the fair value of the SCCS reporting unit was less than its carrying value; therefore, we proceeded to step two of the goodwill impairment analysis. Step two of the goodwill impairment analysis measures the impairment charge by allocating the reporting unit's fair value to all of the assets and liabilities of the reporting unit in a hypothetical analysis that calculates the implied fair value of goodwill in the same manner as if the reporting unit was being acquired in a business combination. This allocation process was performed only for the purposes of measuring the goodwill impairment and not to adjust the carrying values of the recognized tangible assets and liabilities. Any excess of the carrying value of the reporting unit's goodwill over the implied fair value of the reporting unit's goodwill is recorded as an impairment loss. We use a discounted cash flow (“DCF”) approach to estimate the fair value of a reporting unit, utilizing harvest model, which we believe is the most reliable indicator of fair value of this business, and is most consistent with the approach a market place participant would use. Based on our analysis, there was no implied goodwill for the SCCS reporting unit; therefore, we recorded a goodwill impairment charge of $40.7 million in the three months ended March 31, 2013, which represents the remaining goodwill balance in the SCCS reporting unit. None of the goodwill impairment charge was deductible for tax purposes.

Annual Impairment Test

The remaining goodwill is entirely attributable to our Clear Aligner reporting unit. During the fourth quarter of fiscal 2013, we performed the annual goodwill impairment testing and found no impairment events as the fair value of our Clear Aligner reporting unit was significantly in excess of the carrying value.

Acquired Intangible Assets

We amortize our intangible assets over their estimated useful lives. We evaluate long-lived assets, which includes property, plant and equipment and intangible assets, for impairment whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. The carrying value is not recoverable if it exceeds the undiscounted cash flows resulting from the use of the asset and its eventual disposition. Our estimates of future cash flows attributable to our long-lived assets require significant judgment based on our historical and anticipated results and are subject to many factors. Factors we consider important which could trigger an impairment review include significant negative industry or economic trends, significant loss of customers and changes in the competitive environment of our intra-oral scanning business.

During March 2013, changes in the competitive environment for intra-oral scanners, including announcements from our competitors of new low-priced scanners targeted at orthodontists and general practitioner dentists in North America, that caused us to lower our expectations for growth and profitability for our SCCS reporting unit. As a result, we determined that the carrying value of the SCCS long-lived assets was not recoverable as compared to the value of the undiscounted cash flows of our revised projections for the asset group. In order to determine the impairment amount of our long-lived assets, we fair valued each key component of our long-lived assets within the asset group, which involved the use of significant estimates and assumptions including replacement costs, revenue growth rates, operating margins, and plant and equipment cost trends. We use a DCF approach, utilizing the harvest model, to estimate the fair value of a reporting unit, which we believe is the most reliable indicator of fair value of a business, and is most consistent with the approach of a marketplace participant would use. The estimation of fair value utilizing a DCF approach includes numerous uncertainties which require our significant judgment when making assumptions of expected growth rates and the selection of discount rates, as well as assumptions regarding general economic and business conditions, and the structure that would yield the highest economic value, among other factors. Key assumptions used in measuring the fair values of SCCS reporting unit included the discount rate (based on the weighted-average cost of capital) and revenue growth. The fair value of SCCS’s trademark was determined using a risk-adjusted DCF approach under the relief-from-royalty method. The royalty rate used was based on a consideration of market rates. The fair value of SCCS’s finite-lived customer relationships was determined using a DCF approach under the multi-period excess earnings method. We determined our long-lived asset group within the SCCS reporting unit to be primarily finite-lived intangible assets, plant and equipment. Upon completion of this analysis, we recorded a total impairment charge of $26.3 million of which $19.3 million represented the impairment related to our SCCS intangible assets and $7.0 million related to plant and equipment. There was no triggering event related to the Clear Aligner asset group.

Intangible assets arising either as a direct result from the Cadent acquisition or individually acquired are being amortized as follows (in thousands):



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2013		Accumulated Amortization			Impairment Charge			Net Carrying Value as of December 31, 2013
Trademarks	15	$	7,100	$	(1,100	)	$	(4,179	)	$	1,821
Existing technology	13	12,600		(2,236		)	(4,328		)	6,036
Customer relationships	11	33,500		(7,112		)	(10,751		)	15,637
Other	8	285		(40		)	—			245
Total Intangible Assets		$	53,485	$	(10,488	)	$	(19,258	)	$	23,739



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2012		Accumulated Amortization			Net Carrying Value as of December 31, 2012
Trademarks	15	$	7,100	$	(895	)	$	6,205
Existing technology	13	12,600		(1,642		)	10,958
Customer relationships	11	33,500		(5,002		)	28,498
Other	8	125		(9		)	116
Total Intangible Assets		$	53,325	$	(7,548	)	$	45,777

The total estimated annual future amortization expense for these acquired intangible assets as of December 31, 2013 is as follows (in thousands):



Fiscal Year
2014	$	3,053
2015	2,600
2016	2,600
2017	2,600
2018	2,600
Thereafter	10,286
Total	$	23,739

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

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Legal Proceedings	12 Months Ended
Legal Proceedings	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	Legal Proceedings Securities Class Action Lawsuit On November 28, 2012, plaintiff City of Dearborn Heights Act 345 Police & Fire Retirement System filed a lawsuit against Align, Thomas M. Prescott (“Mr. Prescott”), Align's President and Chief Executive Officer, and Kenneth B. Arola (“Mr. Arola”), Align's former Vice President, Finance and Chief Financial Officer, in the United States District Court for the Northern District of California on behalf of a purported class of purchasers of our common stock between April 23, 2012 and October 17, 2012 (the "Securities Action"). On July 11, 2013, an amended complaint was filed, which named the same defendants, on behalf of a purported class of purchasers of our common stock between January 31, 2012 and October 17, 2012. The amended complaint alleged that Align, Mr. Prescott and Mr. Arola violated Section 10(b) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder, and that Mr. Prescott and Mr. Arola violated Section 20(a) of the Securities Exchange Act of 1934. Specifically, the amended complaint alleged that during the purported class period defendants failed to take an appropriate goodwill impairment charge related to the April 29, 2011 acquisition of Cadent Holdings, Inc. in the fourth quarter of 2011, the first quarter of 2012 or the second quarter of 2012, which rendered our financial statements and projections of future earnings materially false and misleading and in violation of U.S. GAAP. The amended complaint sought monetary damages in an unspecified amount, costs and attorney's fees. On December 9, 2013, the judge granted our motion to dismiss with leave for plaintiff to file a second amended complaint. Plaintiff filed a second amended complaint on January 8, 2014 on behalf of the same purported class. The second amended complaint state the same claims as the first amended complaint. We filed a motion to dismiss the second amended complaint on February 7, 2014. Align intends to vigorously defend itself against these allegations. Align is currently unable to predict the outcome of this complaint and therefore cannot determine the likelihood of loss nor estimate a range of possible loss. Shareholder Derivative Lawsuit On February 1, 2013, plaintiff Gary Udis filed a shareholder derivative lawsuit against several of Align's current and former officers and directors in the Superior Court of California, County of Santa Clara. The complaint alleges that our reported income and earnings were materially overstated because of a failure to timely write down goodwill related to the April 29, 2011 acquisition of Cadent Holdings, Inc., and that defendants made allegedly false statements concerning our forecasts. The complaint asserts various state law causes of action, including claims of breach of fiduciary duty, unjust enrichment, and insider trading, among others. The complaint seeks unspecified damages on behalf of Align, which is named solely as nominal defendant against whom no recovery is sought. The complaint also seeks an order directing Align to reform and improve its corporate governance and internal procedures, and seeks restitution in an unspecified amount, costs, and attorney's fees. On July 8, 2013, an Order was entered staying this derivative lawsuit until an initial ruling on our first motion to dismiss the Securities Action. On January 15, 2014, an order was entered staying this derivative lawsuit until an initial ruling on our second motion to dismiss the Securities Action discussed above. Align intends to vigorously defend itself against these allegations. Align is currently unable to predict the outcome of this complaint and therefore cannot determine the likelihood of loss nor estimate a range of possible losses. In addition, in the course of Align's operations, Align is involved in a variety of claims, suits, investigations, and proceedings, including actions with respect to intellectual property claims, patent infringement claims, government investigations, labor and employment claims, breach of contract claims, tax, and other matters. Regardless of the outcome, these proceedings can have an adverse impact on us because of defense costs, diversion of management resources, and other factors. Although the results of complex legal proceedings are difficult to predict and Align's view of these matters may change in the future as litigation and events related thereto unfold; Align currently does not believe that these matters, individually or in the aggregate, will materially affect Align's financial position, results of operations or cash flows.

Credit Facilities	12 Months Ended
Credit Facilities	Dec. 31, 2013
Debt Disclosure [Abstract]
Credit Facilities	Credit Facilities On March 22, 2013, we entered into a credit facility with Wells Fargo Bank. The credit facility provides for a $50.0 million revolving line of credit, with a $10.0 million letter of credit sublimit, and has a maturity date on March 22, 2016. The credit facility also requires us to maintain a minimum unrestricted cash balance of $50.0 million and comply with specific financial conditions and performance requirements. The loans bear interest, at our option, at a fluctuating rate per annum equal to the daily one-month adjusted LIBOR rate plus a spread of 1.75% or an adjusted LIBOR rate (based on one, three, six or twelve-month interest periods) plus a spread of 1.75%. As of December 31, 2013, we had no outstanding borrowings under this credit facility and were in compliance with the conditions and performance requirements.

Commitments and Contingencies Disclosure [Abstract]

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References+ Details

Commitments and Contingencies

12 Months Ended

Dec. 31, 2013

Commitments and Contingencies

Operating leases

We lease our facilities and certain equipment and automobiles under non-cancelable operating lease arrangements that expire at various dates through 2022 and provide for pre-negotiated fixed rental rates during the terms of the lease. The terms of some of our leases provide for rental payments on a graduated scale. We recognize rent expense on a straight-line basis over the lease period and accrue for any rent expense incurred but not paid. Total rent expense was $7.3 million, $6.9 million and $6.1 million, for the years ended December 31, 2013, 2012 and 2011, respectively.

Minimum future lease payments for non-cancelable leases as of December 31, 2013, are as follows (in thousands):



Fiscal Year	Operating leases
2014	$	7,878
2015	7,463
2016	6,708
2017	4,316
2018	1,483
Thereafter	425
Total minimum lease payments	$	28,273

Off-balance Sheet Arrangements

As of December 31, 2013, we had no off-balance sheet arrangements that have, or are reasonably likely to have, a current or future material effect on our consolidated financial condition, results of operations, liquidity, capital expenditures or capital resources.

Indemnification Provisions

In the normal course of business to facilitate transactions in our services and products, we indemnify certain parties: customers, vendors, lessors, and other parties with respect to certain matters, including, but not limited to, services to be provided by us and intellectual property infringement claims made by third parties. In addition, we have entered into indemnification agreements with our directors and certain of our officers that will require us, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. Several of these agreements limit the time within which an indemnification claim can be made and the amount of the claim.

It is not possible to make a reasonable estimate of the maximum potential amount under these indemnification agreements due to the unique facts and circumstances involved in each particular agreement. Additionally, we have a limited history of prior indemnification claims and the payments we have made under such agreements have not had a material adverse effect on our results of operations, cash flows, or financial position. However, to the extent that valid indemnification claims arise in the future, future payments by us could be significant and could have a material adverse effect on our results of operations or cash flows in a particular period. As of December 31, 2013, we did not have any material indemnification claims that were probable or reasonably possible.

Stockholders' Equity Note [Abstract]

The entire disclosure for commitments and contingencies.

+ References+ Details

Stockholders' Equity

12 Months Ended

Dec. 31, 2013

Stockholders' Equity

Stockholders’ Equity

Preferred Stock Rights Agreement

The Preferred Stock Rights Agreement (the “Rights Agreement”) is intended to protect stockholders from unfair or coercive takeover practices. In accordance with the Rights Agreement, the Board of Directors declared a dividend distribution of one preferred stock purchase right (a “Right”) for each outstanding share of our common stock to stockholders of record on November 22, 2005. Each Right entitles stockholders to buy one one-thousandth of a share of our Series A Participating Preferred Stock, par value $0.0001 per share, at an exercise price of $37.00, subject to adjustment. Rights will become exercisable upon the occurrence of certain events, including a person or group acquiring or the announcing the intention to acquire beneficial ownership of 15% or more of the then outstanding common stock without the approval of the Board of Directors. Each holder of a Right will have the right to receive, upon exercise, shares of common stock having a value equal to two times the purchase price. The Rights will expire on November 22, 2015 or upon the exercise of the Rights, whichever occurs earlier.

Common Stock

The holders of common stock are entitled to receive dividends whenever funds are legally available and when and if declared by the Board of Directors. We have never declared or paid dividends on our common stock.

Stock-based Compensation Plans

Our 2005 Incentive Plan, as amended, provides for the granting of incentive stock options, non-statutory stock options, restricted stock units, market stock units, stock appreciation rights, performance units and performance shares to employees, non-employee directors, and consultants. Shares granted on or after May 16, 2013 as an award of restricted stock, restricted stock unit, market stock units, performance share or performance unit ("full value awards") are counted against the authorized share reserve as one and nine-tenths (19/10) shares for every one (1) share subject to the award, and any shares canceled that were counted as one and nine-tenths against the plan reserve will be returned at the same ratio. Full value awards granted prior to May 16, 2013 were counted against the authorized share reserve as one and one half (1 1/2) share for every one (1) share subject to the award, and any shares canceled that were counted as one and one half against the plan reserve will be returned at this same ratio.

On May 16, 2013, the Stockholders approved an increase of 7,000,000 shares to the 2005 Incentive Plan (as amended) for a total reserve of 23,283,379 shares for issuance, plus up to an aggregate of 5,000,000 shares that would have been returned to our 2001 Stock Incentive Plan as a result of termination of options on or after March 28, 2005.

As of December 31, 2013, we have a total of 23,283,379 shares authorized and reserved, of which 9,119,512 shares are available for issuance. This includes 2,384,516 shares that have been transferred from the 2001 Stock Incentive Plan. We issue new shares from our pool of authorized but unissued shares to satisfy the exercise and vesting obligations of our stock-based compensation plans.

Stock-based Compensation

Stock-based compensation is based on the estimated fair value of awards, net of estimated forfeitures, and recognized over the requisite service period. Estimated forfeitures are based on historical experience at the time of grant and may be revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The stock-based compensation related to all of our stock-based awards and employee stock purchases for the year ended December 31, 2013, 2012 and 2011 is as follows (in thousands):



	For the Year Ended December 31,
	2013		2012		2011
Cost of net revenues	$	2,565	$	1,843	$	1,818
Sales and marketing	7,093		5,581		5,495
General and administrative	13,261		10,361		9,096
Research and development	3,519		3,698		2,756
Total stock-based compensation	$	26,438	$	21,483	$	19,165

Stock Options

Options are granted for terms not to exceed seven years and generally vest over four years with 25% vesting one year from the date of grant and 1/48th each month thereafter. Activity for the year ended December 31, 2013, under the stock option plans are set forth below (in thousands, except years and per share amounts):



	Stock Options
	Number of Shares Underlying Stock Options		Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (in years )	Aggregate Intrinsic Value
Outstanding as of December 31, 2012	3,276		15.21
Granted	—		—
Exercised	(1,863	)	14.57
Cancelled or expired	(92	)	15.35
Outstanding as of December 31, 2013	1,321		$	16.08	3.61	$	54,231
Vested and expected to vest at December 31, 2013	1,317		$	16.06	3.61	$	54,102
Exercisable at December 31, 2013	1,205		$	15.65	3.59	$	49,996

The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between our closing stock price on the last trading day in 2013 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2013. This amount will fluctuate based on the fair market value of our stock. The total intrinsic value of stock options exercised for the years ended December 31, 2013, 2012 and 2011 was $46.7 million, $50.9 million and $23.7 million, respectively. The total fair value of the options vested during the years ended December 31, 2013, 2012 and 2011 was $3.7 million, $5.0 million and $9.2 million, respectively. There were no stock options granted in 2013.

The fair value of stock options granted was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:



	2013			2012			2011
Stock options ¹:
Expected term (in years)	—			—			4.4
Expected volatility	—		%	—		%	60.6		%
Risk-free interest rate	—		%	—		%	1.7		%
Expected dividends	—			—			—
Weighted average fair value at grant date	$	—		$	—		$	10.87

¹There were no stock options granted in 2013 or 2012.

The expected term of stock options represents the weighted-average period the stock options are expected to remain outstanding. We used a mid-point model to determine the expected term of stock options based on our historical exercise, post-vesting cancellation experience, and the remaining contractual term of our outstanding options.

We use our own historical volatility.

The risk-free interest rate is based on the implied yield on a U.S. Treasury zero-coupon issue with a remaining term equal to the expected term of the option.

We have not paid any cash dividends since inception and do not anticipate paying cash dividends in the foreseeable future, therefore we used an expected dividend of zero.

As of December 31, 2013, there was $1.3 million, net of estimated forfeitures, of total unamortized compensation costs related to stock options and these costs are expected to be recognized over a weighted average period of 0.9 years. For the year ended December 31, 2013, the total recognized tax effect from exercised options was $0.9 million.

Restricted Stock Units

The fair value of nonvested restricted stock units (“RSUs”) is based on our closing stock price on the date of grant. A summary for the year ended December 31, 2013, is as follows (in thousands, except years and per share amounts):



	Shares Underlying RSUs		Average Grant Date Fair Value Price per Share		Weighted Remaining Vesting Period (in years)	Aggregate Intrinsic Value
Nonvested as of December 31, 2012	1,500		$	23.95
Granted	1,289		36.38
Vested and released	(573	)	22.90
Forfeited	(172	)	26.37
Nonvested as of December 31, 2013	2,044		$	31.88	1.44	$	116,818

The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (calculated by multiplying our closing stock price on the last trading day of 2013 by the number of nonvested RSUs) that would have been received by the unit holders had all RSUs been vested and released on December 31, 2013. This amount will fluctuate based on the fair market value of our stock. During 2013, of the 572,815 shares vested and released, approximately 80,435 vested shares were withheld for executive RSUs minimum statutory tax obligations, resulting in a net issuance of 492,380 shares. Total payments to tax authorities for payroll taxes related to RSUs, including market-performance based restricted stock units, that vested during the period for executive officers were $4.4 million, $2.1 million and $1.9 million in 2013, 2012 and 2011, respectively, reflected as a financing activity in the Consolidated Statements of Cash Flows.

The total intrinsic value of RSUs vested and released during 2013, 2012 and 2011 was $20.3 million, $12.5 million and $8.9 million, respectively. The total fair value RSUs vested during the years ended December 31, 2013, 2012, and 2011 was $13.2 million, $7.8 million, and $5.8 million, respectively. As of December 31, 2013, there was $46.9 million of total unamortized compensation costs, net of estimated forfeitures, related to RSUs, and these costs are expected to be recognized over a weighted average period of 2.6 years.

On an annual basis, we grant market-performance based restricted stock units (“MSUs”) to our executive officers. Each MSU represents the right to one share of Align’s common stock and will be issued through our amended 2005 Incentive Plan. The actual number of MSUs which will be eligible to vest will be based on the performance of Align’s stock price relative to the performance of the NASDAQ Composite Index over the vesting period, generally two to three years, up to 150% of the MSUs initially granted.

The following table summarizes the MSU performance as of December 31, 2013:



	Number of Shares Underlying MSUs (in thousands)		Weighted Average Remaining Vesting Period (in years )	Aggregate Intrinsic Value (in thousands)
Nonvested as of December 31, 2012	266
Granted	225
Vested and released	(96	)
Forfeited	(88	)
Nonvested as of December 31, 2013	307		1.57	$	17,556

The total intrinsic value of MSUs vested and released during 2013 was $3.2 million. The total fair value MSUs vested during the years ended December 31, 2013 was $1.5 million. As of December 31, 2013, we expect to recognize $5.8 million of total unamortized compensation cost, net of estimated forfeitures, related to MSU over a weighted average period of 1.6 years.

The fair value of the MSUs is estimated at the grant date using a Monte Carlo simulation that includes factors for market conditions. The following weighted-average assumptions used in the Monte Carlo simulation were as follows:



	Year Ended December 31,
	2013			2012			2011
Expected term (in years)	3			3			3
Expected volatility	47.0		%	54.0		%	58.4		%
Risk-free interest rate	0.4		%	0.4		%	1.3		%
Expected dividends	—			—			—
Weighted average fair value per share at grant date	$	35.49		$	29.45		$	22.12

Employee Stock Purchase Plan

In May 2010, our shareholders approved the 2010 Employee Stock Purchase Plan (the “2010 Purchase Plan”), replacing our 2001 Employee Stock Purchase Plan, which consists of consecutive overlapping twenty-four month offering periods with four six-month purchase periods in each offering period. Employees purchase shares at 85% of the fair market value of the common stock at either the beginning of the offering period or the end of the purchase period, whichever is lower. The 2010 Purchase Plan will continue until terminated by either the Board or its administrator. The maximum number of shares available for issuance under the 2010 Purchase Plan is 2,400,000 shares. During the year ended December 31, 2013, 2012 and 2011, we issued 288,675, 336,382, and 482,542 shares, respectively, at average prices of $21.96, $17.98, and $10.63, respectively. As of December 31, 2013, 1,611,170 shares remain available for future issuance.

The fair value of the option component of the Purchase Plan shares was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:



	December 31,
	2013			2012			2011
Employee Stock Purchase Plan:
Expected term (in years)	1.2			1.2			1.5
Expected volatility	44.9		%	49.7		%	43.2		%
Risk-free interest rate	0.2		%	0.2		%	0.4		%
Expected dividends	—			—			—
Weighted average fair value at grant date	$	11.69		$	11.10		$	7.29

We recognized stock-based compensation expense of $3.4 million, $2.0 million and $3.1 million related to our employee stock purchase plans for the years ended December 31, 2013, 2012 and 2011, respectively. As of December 31, 2013, there was $1.9 million of total unamortized compensation costs related to employee stock purchases. These costs are expected to be recognized over a weighted average period of 0.6 years.

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

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+ Details

Employee Benefit Plans	12 Months Ended
Employee Benefit Plans	Dec. 31, 2013
Compensation Related Costs [Abstract]
Employee Benefit Plans	Employee Benefit Plans 401(k) Plan In January 1999, we adopted a defined contribution retirement plan under Section 401(k) of the Internal Revenue Code for our U.S. employees. This plan covers substantially all U.S. employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. In 2009, our Board of Directors authorized us to match 50% of our employee’s salary deferral contributions up to a 6% of the employee’s eligible compensation effective 2010. We contributed approximately $2.1 million, $1.9 million and $1.8 million to the 401(k) plan during 2013, 2012 and 2011, respectively. Israeli Funds Under the Israeli severance fund law, we are required to make payments to dismissed employees and employees leaving employment in certain circumstances. The funding is calculated based on the salary of the employee multiplied by the number of years of employment as of the applicable balance sheet date. Our Israeli employees are entitled to one month’s salary for each year of employment, or a pro-rata portion thereof. We fund the liability through monthly deposits into funds, and the values of these contributions are recorded in other long-term current assets. As of December 31, 2013 and 2012, the accrued funds liability was approximately $2.4 million and $2.7 million, respectively.

Income Taxes

12 Months Ended

Dec. 31, 2013

Income Tax Disclosure [Abstract]

Income Taxes

Income before provision for income taxes consisted of the following (in thousands):



	Year ended December 31,
	2013		2012		2011
Domestic	$	31,993	$	32,341	$	52,184
Foreign	61,146		51,955		37,757
Total Income before provision for income taxes	$	93,139	$	84,296	$	89,941

The provision for income taxes consisted of the following (in thousands):



	Year Ended December 31,
	2013			2012		2011
Federal
Current	$	26		$	—	$	65
Deferred	24,262			22,382		21,026
	24,288			22,382		21,091
State
Current	1,235			438		224
Deferred	1,158			1,486		1,394
	2,393			1,924		1,618
Foreign
Current	3,113			1,173		1,263
Deferred	(950		)	126		(747		)
	2,163			1,299		516
Provision for income taxes	$	28,844		$	25,605	$	23,225

The differences between income taxes using the federal statutory income tax rate of 35% and our effective tax rate were as follows:



	Year Ended December 31,
	2013		2012		2011
U.S. federal statutory income tax rate	35.00	%	35.00	%	35.00	%
State income taxes, net of federal tax benefit	2.54		2.36		1.58
Impact of differences in foreign tax rates	(20.41	)	(20.00	)	(14.99	)
Goodwill Impairment	15.29		15.19		—
Stock-based compensation	0.47		(1.15	)	1.67
Non-deductible transaction fees	—		—		1.29
Valuation allowance release	—		—		(0.14	)
Other items not individually material	(1.92	)	(1.02	)	1.41
	30.97	%	30.38	%	25.82	%

As of December 31, 2013, U.S. income taxes and foreign withholding taxes associated with the repatriation of undistributed earnings of foreign subsidiaries were not provided for on a cumulative total of $186.4 million. We intend to reinvest these earnings indefinitely in our foreign subsidiaries. If these earnings were distributed in the form of dividends or otherwise, or if the shares of the relevant foreign subsidiaries were sold or otherwise transferred, we would be subject to additional U.S. income taxes and foreign withholding taxes, net of related foreign tax credits. Determination of the amount of unrecognized deferred income tax liability related to these earnings is not practicable.

In June 2009, the Costa Rica Ministry of Foreign Trade, an agency of the Government of Costa Rica, granted a twelve year extension of certain tax incentives, which were previously granted in 2002. The incentive tax rates will expire in various years beginning in 2017. Under these incentives, all of the income in Costa Rica during these twelve year incentive periods is subject to reduced rates of Costa Rica income tax. In order to receive the benefit of the incentives, we must hire specified numbers of employees and maintain minimum levels of fixed asset investment in Costa Rica. If we do not fulfill these conditions for any reason, our incentive could lapse and our income in Costa Rica would be subject to taxation at higher rates, which could have a negative impact on our operating results. The Costa Rica corporate income tax rate that would apply, absent the incentives, is 30% for 2013. As a result of these incentives, income taxes were reduced by $27.7 million, $21.8 million, and $15.4 million in 2013, 2012, and 2011, respectively. The benefit of the tax holiday on net income per share (diluted) was $0.34, $0.26, $0.19 in 2013, 2012 and 2011, respectively.

As of December 31, 2013 and December 31, 2012, the significant components of our deferred tax assets and liabilities were (in thousands):



	Year Ended December 31,
	2013			2012
Deferred tax assets:
Net operating loss and capital loss carryforwards	$	39,978		$	37,183
Credit carryforwards	9,362			8,806
Reserves and accruals	26,729			19,703
Translation gains	48			43
Stock-based compensation	9,100			9,908
	85,217			75,643
Deferred tax liabilities:
Prepaid expenses	557			345
Depreciation and amortization	5,320			9,903
	5,877			10,248
Net deferred tax assets before valuation allowance	79,340			65,395
Valuation allowance	(35,108		)	(27,056		)
Net deferred tax assets	$	44,232		$	38,339

We assess the likelihood that we will be able to realize our deferred tax assets. We consider all available evidence, both positive and negative, including historical levels of income, expectations and risks associated with estimates of future taxable income and ongoing prudent and feasible tax planning strategies in assessing the need for a valuation allowance. If it is more likely than not that we do not expect to realize our deferred tax assets, we will increase our provision for income taxes by recording a valuation allowance against the deferred tax assets that we estimate will not ultimately be realizable. As of December 31, 2013, we believed, except for the items noted in the subsequent paragraph, that it was more likely than not that the amount of deferred tax assets recorded on the balance sheet will be realized.

The $35.1 million total valuation allowance provided against our deferred tax assets at December 31, 2013 relates primarily to foreign net operating loss carryforwards. The valuation allowance increased by a net $8.0 million, due to a $9.8 million increase related to foreign net operating loss carryforwards, offset by a decrease of $1.8 million due to the statute of limitations having lapsed with respect to certain operating loss carryforward deferred tax assets.

At December 31, 2013, we had net operating loss carryforwards of approximately $42.4 million for federal purposes and $56.7 million for California state tax purposes. If not utilized, these carryforwards will begin to expire in 2026 for federal purposes and 2014 for California purposes. In addition, we had foreign net operating loss carryforwards of approximately $36.7 million, which, if not utilized will expire beginning in 2014.

Our net operating loss carryforwards associated with the exercise of employee stock options totaled $25.2 million as of December 31, 2013. Our income taxes payable for federal purposes have been reduced by the tax benefits associated with the exercise of employee stock options during the fiscal year, and utilization of net operating loss carryover applicable to stock options. The benefits applicable to stock options were credited directly to stockholders’ equity when realized. We follow the tax law ordering method to determine when excess tax benefits have been realized and consider only the direct impacts of awards when calculating the amount of windfalls or shortfalls.

We have research credit carryforwards of approximately $5.9 million for federal purposes and $3.6 million for California state tax purposes. If not utilized, the federal credit carryforwards will begin to expire in 2020. The California state credit can be carried forward indefinitely.

In the event of a change in ownership, as defined under federal and state tax laws, our net operating loss and tax credit carryforwards may be subject to annual limitations. The annual limitations may result in the expiration of the net operating loss and tax credit carryforwards before utilization.

The changes in the balance of gross unrecognized tax benefits, which exclude interest and penalties, for fiscal year ended December 31, 2013, 2012, and 2011, is as follows (in thousands):



Unrecognized tax benefit as of December 31, 2011	$	15,472
Tax positions related to current year:
Additions for uncertain tax positions	5,087
Tax positions related to prior year:
Additions for uncertain tax positions	80
Unrecognized tax benefit as of December 31, 2012	20,639
Tax positions related to current year:
Additions for uncertain tax positions	6,110
Tax positions related to prior year:
Decreases for uncertain tax positions	(81		)
Unrecognized tax benefit as of December 31, 2013	$	26,668

We account for uncertain tax issues pursuant to authoritative guidance based on a two-step approach to recognize and measure uncertain tax positions taken or expected to be taken in a tax return. We first determine whether it is more likely than not that a tax position will be sustained upon audit based on its technical merits. If a tax position meets the more-likely-than-not recognition threshold it is then measured to determine the amount of benefit to recognize in the financial statements. The tax position is measured as the largest amount of benefit that is more than 50 percent likely to be realized upon ultimate settlement. We adjust reserves for our uncertain tax positions due to changing facts and circumstances, such as the closing of a tax audit, or refinement of estimates due to new information. To the extent the final outcome of these matters is different than the amounts recorded, such differences will impact our tax provision in our Consolidated Statements of Operations in the period in which such determination is made.

During fiscal year 2013, the amount of gross unrecognized tax benefits increased by $6.0 million. The total amount of unrecognized tax benefits was $26.7 million as of December 31, 2013, all of which would impact our effective tax rate if recognized. We have elected to recognize interest and penalties related to unrecognized tax benefits as a component of income tax expense. The penalties and interest accrued as of December 31, 2013 and 2012 are immaterial. We do not expect any significant changes to the amount of unrecognized tax benefits within the next twelve months.

We are subject to taxation and audits in the U.S. and various states and foreign jurisdictions. All of our tax years will be open to examination by the U.S. federal and most state tax authorities due to our net operating loss and overall credit carryforward position. With few exceptions, we are no longer subject to examination by foreign tax authorities for years before 2006.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References+ Details

Net Income per Share

12 Months Ended

Dec. 31, 2013

Earnings Per Share [Abstract]

Net Income per Share

Basic net income per share is computed using the weighted average number of shares of common stock outstanding during the period. Diluted net income per share is computed using the weighted average number of shares of common stock, adjusted for the dilutive effect of potential common stock. Potential common stock, computed using the treasury stock method, includes options, RSUs, MSUs and our employee stock purchase plan.

The following table sets forth the computation of basic and diluted net income per share attributable to common stock (in thousands, except per share amounts):



	Year Ended December 31,
	2013		2012		2011
Numerator:
Net income	$	64,295	$	58,691	$	66,716
Denominator:
Weighted-average common shares outstanding, basic	80,551		80,529		77,988
Dilutive effect of potential common stock	2,038		2,511		2,306
Total shares, diluted	82,589		83,040		80,294
Net income per share, basic	$	0.80	$	0.73	$	0.86
Net income per share, diluted	$	0.78	$	0.71	$	0.83

For the years ended December 31, 2013, 2012 and 2011 stock options, RSUs, MSUs and our employee stock purchase plan totaling 0.1 million, 0.1 million and 1.6 million, respectively, were excluded from diluted net income per share because of their anti-dilutive effect.

Supplemental Cash Flow Information [Abstract]

The entire disclosure for earnings per share.

+ References+ Details

Supplemental Cash Flow Information

12 Months Ended

Dec. 31, 2013

Supplemental Cash Flow Information

The supplemental cash flow information consists of the following (in thousands):



	Year Ended December 31,
	2013		2012		2011
Taxes paid	$	4,125	$	2,825	$	1,953
Non-cash investing and financing activities:
Fixed assets acquired with accounts payable or accrued liabilities	$	2,308	$	940	$	1,611
Unclaimed merger consideration liability	$	—	$	1,575	$	—

Segments and Geographical Information

12 Months Ended

Dec. 31, 2013

Segment Reporting [Abstract]

Segments and Geographical Information

Segment Information

Operating segments are defined as components of an enterprise for which separate financial information is available that is evaluated regularly by the Chief Operating Decision Maker (“CODM”), or decision-making group, in deciding how to allocate resources and in assessing performance. Our CODM is our Chief Executive Officer. We report segment information based on the management approach. The management approach designates the internal reporting used by CODM for decision making and performance assessment as the basis for determining our reportable segments. The performance measures of our reportable segments include net revenues and gross profit.

We have grouped our operations into two reportable segments which are also our reporting units: Clear Aligner segment and SCCS segment.


•	Our Clear Aligner segment consists of our Invisalign System which includes Invisalign Full, Express/Lite, Teen, Assist, Vivera Retainers, along with our training and ancillary products for treating malocclusion.


•	Our SCCS segment consists of intra-oral scanning systems and additional services available with the intra-oral scanners that provide digital alternatives to the traditional cast models. This segment includes our iTero scanner and OrthoCAD services and was the result of our acquisition of Cadent on April 29, 2011.

These reportable operating segments are based on how our CODM views and evaluates our operations as well as allocation of resources. The following information relates to these segments (in thousands):



	For the Year Ended December 31,
Net Revenues	2013		2012		2011
Clear Aligner
Invisalign Full	$	382,054	$	338,600	$	302,391
Invisalign Express/Lite	72,418		51,486		42,509
Invisalign Teen	84,850		67,127		54,529
Invisalign Assist	30,603		28,705		27,527
Invisalign non-case revenues	44,724		30,663		24,757

SCCS
Scanners	23,698		20,059		13,383
CAD/CAM Services	21,859		23,401		14,645
Total net revenues	$	660,206	$	560,041	$	479,741

Gross Profit
Clear Aligner	$	484,835	$	405,970	$	354,700
SCCS	13,271		10,418		6,583
Total gross profit	$	498,106	$	416,388	$	361,283

Geographical Information

Net revenues and long-lived assets are presented below by geographic area (in thousands):



	For the Year Ended December 31,
	2013		2012		2011
Net revenues ¹:
United States	$	491,410	$	427,929	$	359,936
the Netherlands	127,769		105,942		97,910
Other international	41,027		26,170		21,895
Total net revenues	$	660,206	$	560,041	$	479,741



	As of December 31,
	2013		2012		2011
Long-lived assets ²:
United States	$	61,439	$	60,098	$	43,868
Mexico	6,291		6,473		4,673
the Netherlands	1,630		1,383		343
Other international	6,383		11,237		5,081
Total long-lived assets	$	75,743	$	79,191	$	53,965


¹	Net revenues are attributed to countries based on location of where revenue is recognized.


²	Long-lived assets are attributed to countries based on entity that owns the assets.

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

Restructurings and Exit Activities

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+ Details

Exit Activities

12 Months Ended

Dec. 31, 2013

Restructuring Reserve [Abstract]

Exit Activities

In October 2012, we completed the consolidation of our CAD/CAM services and intra-oral scanner-related activities for our SCCS segment based in Carlstadt, New Jersey with our existing manufacturing and shared services organizations in order to optimize efficiency, consolidate customer-facing functions, and reduce operating costs. All existing intra-oral scanner research and development and manufacturing operations remain in Or Yehuda, Israel. The transition included the following activities:


•	Consolidation of customer care for CAD/CAM services and intra-oral scanners into our existing shared services organization in San Jose, Costa Rica;


•	Transition of CAD/CAM services and intra-oral scanner distribution and repair to our Treat operations in San Jose, Costa Rica and our new manufacturing facility in Juarez, Mexico; and


•	Consolidation of accounting and finance functions at our corporate headquarters in San Jose, California.

The consolidation of our New Jersey operations, which began in the fourth quarter of 2011, resulted in a total reduction of 119 full time headcount in Carlstadt, New Jersey.

During 2012, we incurred approximately $0.8 million in exit costs of which approximately $0.5 million were recorded in our cost of revenue and $0.3 million in operating expenses. There were no exit costs in 2013.

Valuation and Qualifying Accounts [Abstract]

The entire disclosure for restructuring and related activities. Description of restructuring activities such as exit and disposal activities, include facts and circumstances leading to the plan, the expected plan completion date, the major types of costs associated with the plan activities, total expected costs, the accrual balance at the end of the period, and the periods over which the remaining accrual will be settled.

+ References+ Details

Schedule II: Valuation and Qualifying Accounts and Reserves

12 Months Ended

Dec. 31, 2013

Schedule II: Valuation and Qualifying Accounts and Reserves

SCHEDULE II: VALUATION AND QUALIFYING ACCOUNTS AND RESERVES



	Balance at Beginning of Period		Additions (reductions) to Costs and Expenses			Write offs			Charged to Other Accounts ¹		Reclass from Other Accounts			Balance at End of Period
	(in thousands)
Allowance for doubtful accounts and returns:
Year ended December 31, 2011	$	1,247	$	2,571		$	(2,316	)	$	—	$	(2	)	$	1,500
Year ended December 31, 2012	$	1,500	$	4,417		$	(2,735	)	$	—	$	(15	)	$	3,167
Year ended December 31, 2013	$	3,167	$	2,116		$	(3,550	)	$	—	$	—		$	1,733
Valuation Allowance for deferred tax assets:
Year ended December 31, 2011	$	6,079	$	(680	)	$	—		$	14,825	$	—		$	20,224
Year ended December 31, 2012	$	20,224	$	8,507		$	(1,675	)	$	—	$	—		$	27,056
Year ended December 31, 2013	$	27,056	$	9,806		$	(1,754	)	$	—	$	—		$	35,108


¹	For the year ended December 31, 2011, we increased the valuation allowance in connection with acquired deferred tax assets and non-U.S. net operating losses, which resulted in a corresponding increase to goodwill, related to the Cadent acquisition.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2013

Accounting Policies [Abstract]

Earnings Per Share, Policy [Policy Text Block]

Business Description

Basis of presentation and preparation

Use of estimates

Fair value of financial instruments

The carrying amounts of our cash, accounts receivable, accounts payable and other current liabilities approximate their fair value.

Level 1— Quoted (unadjusted) prices in active markets for identical assets or liabilities.

Level 3 – Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability.

Cash and cash equivalents

Restricted cash

Marketable Securities

Marketable securities

We invest primarily in money market funds, commercial paper, corporate bonds, U.S. dollar dominated foreign corporate bonds, U.S. government agencies and municipal bonds.

Foreign currency

Certain risks and uncertainties

Inventories

Property, plant and equipment

Goodwill and finite-lived purchased intangible assets

Goodwill and finite-lived acquired intangible assets

Impairment of goodwill, finite-lived purchased intangible assets and long-lived assets

Impairment of goodwill and long-lived assets

Goodwill

Finite-lived intangible assets and long-lived assets

Development costs for internal use software

Product Warranty

Clear Aligner

Scanners and CAD/CAM Services

Allowance for Doubtful Accounts

Allowance for Doubtful Accounts and Returns

Revenue recognition

Revenue Recognition

•


•	TPE – If we cannot establish VSOE of selling price for a specific product or service included in a multiple-element arrangement, we use third-party evidence of selling price. We determine TPE based on sales of comparable amount of similar products or service offered by multiple third parties considering the degree of customization and similarity of product or service sold.

•

Provisions for discounts and rebates to customers are provided for in the same period that the related product sales are recorded based upon historical discounts and rebates.

Clear Aligner

Scanners and CAD/CAM Services

Shipping and Handling Costs

Shipping and handling charges to customers are included in net revenues, and the associated costs incurred are recorded in cost of revenues.

Legal Proceedings and Litigations

Research and development

Advertising costs

The cost of advertising and media is expensed as incurred.

Common Stock Repurchase

Common stock repurchase

Operating Leases

Operating leases

Income taxes

Stock-based compensation

Comprehensive income (loss)

Recent Accounting Pronouncements

Marketable Securities and Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2013

Investments, All Other Investments [Abstract]

Short-Term And Long-Term Marketable Securities

As of December 31, 2013 and 2012, the estimated fair value of our short-term and long-term investments, classified as available for sale, are as follows (in thousands):

Short-term



December 31, 2013	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	54,318	$	10	$	—		$	54,328
Corporate bonds	29,079		10		(4		)	29,085
U.S. dollar dominated foreign corporate bonds	13,959		12		—			13,971
Municipal securities	7,006		11		(3		)	7,014
U.S. government agency bonds	16,693		10		—			16,703
Asset-backed securities	5,937		2		—			5,939
Total Marketable Securities, Short-Term	$	126,992	$	55	$	(7	)	$	127,040

Long-term



December 31, 2013	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	38,138	$	1	$	(21	)	$	38,118
Corporate bonds	23,308		14		(9		)	23,313
U.S. dollar dominated foreign corporate bonds	19,485		27		(17		)	19,495
U.S. government treasury bonds	6,916		3		—			6,919
Municipal securities	8,326		13		(8		)	8,331
Asset-backed securities	5,800		4		(2		)	5,802
Total Marketable Securities, Long-Term	$	101,973	$	62	$	(57	)	$	101,978

Short-term



December 31, 2012	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	4,646	$	1	$	—		$	4,647
Corporate bonds	18,767		7		(4		)	18,770
U.S. dollar dominated foreign corporate bonds	5,060		9		(1		)	5,068
Total Marketable Securities, Short-Term	$	28,473	$	17	$	(5	)	$	28,485

Long-term



December 31, 2012	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Corporate bonds	$	16,132	$	16	$	(7	)	$	16,141
U.S. dollar dominated foreign corporate bonds	3,038		4		(1		)	3,041
U.S. government agency bonds	2,069		1		—			2,070
Total Marketable Securities, Long-Term	$	21,239	$	21	$	(8	)	$	21,252

Marketable Securities



	December 31,		December 31,
	2013		2012
One year or less	$	127,040	$	28,485
One year through two years	101,978		21,252
	$	229,018	$	49,737

Financial Assets Measured At Fair Value On A Recurring Basis

The following table summarizes our financial assets measured at fair value on a recurring basis as of December 31, 2013and 2012 (in thousands):



Description	Balance as of December 31, 2013		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	143,540	$	143,540	$	—
Commercial paper	15,398		—		15,398
Short-term investments:
Commercial paper	54,328		—		54,328
Corporate bonds	29,085		—		29,085
U.S. dollar denominated foreign corporate bonds	13,971		—		13,971
Municipal securities	7,014		—		7,014
U.S. government agency bonds	16,703		—		16,704
Asset-backed securities	5,939		—		5,938
Long-term investments:
Corporate bonds	23,313		—		23,313
U.S. government agency bonds	38,118		—		38,118
U.S. dollar denominated foreign corporate bonds	19,495		—		19,495
U.S. government treasury bonds	6,919		6,919		—
Municipal securities	8,331		—		8,331
Asset-backed securities	5,802		—		5,802
Long-term other assets:
Israeli funds	2,193		—		2,193
	$	390,149	$	150,459	$	239,690



Description	Balance as of December 31, 2012		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	86,166	$	86,166	$	—
Commercial paper	950		—		950
Short-term investments:
Commercial paper	4,647		—		4,647
Corporate bonds	18,770		—		18,770
U.S. dollar denominated foreign corporate bonds	5,068		—		5,068
Long-term investments:
U.S. government agency bonds	2,070		—		2,070
Corporate bonds	16,141		—		16,141
U.S. dollar denominated foreign corporate bonds	3,041		—		3,041
Long-term other assets:
Israeli funds	2,218		—		2,218
	$	139,071	$	86,166	$	52,905

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

+ References+ Details

Balance Sheet Related Disclosures [Abstract]

Tabular disclosure of marketable securities. This may consist of investments in certain debt and equity securities, short-term investments and other assets.

+ References+ Details

Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2013

Schedule of Inventories

Inventories consist of the following (in thousands):



	December 31,
	2013		2012
Raw materials	$	5,172	$	7,629
Work in process	4,241		3,889
Finished goods	4,555		3,604
Total Inventories	$	13,968	$	15,122

Property and Equipment

Property, plant and equipment consist of the following (in thousands):



	December 31,
	2013			2012
Clinical and manufacturing equipment	$	104,373		$	83,821
Computer hardware	24,851			22,706
Computer software	21,286			20,346
Furniture and fixtures	7,275			6,808
Leasehold improvements	14,996			12,388
Building	1,868			1,868
Land	1,162			1,162
Construction in progress	5,438			16,027
Total	181,249			165,126
Less: Accumulated depreciation and amortization and impairment charges ¹	(105,506		)	(85,935		)
Total Property, plant and equipment, net	$	75,743		$	79,191

Schedule of Accrued Liabilities

Accrued liabilities consist of the following (in thousands):



	December 31,
	2013		2012
Accrued payroll and benefits	$	43,029	$	39,621
Accrued sales rebate	10,100		8,333
Accrued sales tax and value added tax	6,215		5,253
Accrued sales and marketing expenses	3,893		4,088
Accrued warranty	3,104		4,050
Accrued accounts payable	2,764		2,866
Accrued professional fees	1,892		2,349
Accrued income taxes	1,205		572
Other accrued liabilities	8,143		7,115
Total Accrued Liabilities	$	80,345	$	74,247

Warranty accrual

Warranty accrual as of December 31, 2013 and 2012 consists of the following activity (in thousands):



Warranty accrual, December 31, 2011	$	3,177
Charged to cost of revenues	4,637
Actual warranty expenditures	(3,764		)
Warranty accrual, December 31, 2012	4,050
Charged to cost of revenues	2,850
Actual warranty expenditures	(3,796		)
Warranty accrual, December 31, 2013	$	3,104

Business Combinations (Tables)

12 Months Ended

Dec. 31, 2013

Business Combinations [Abstract]

Schedule of Purchase Price

The following table summarizes the allocation of the purchase price as of April 29, 2011 (in thousands):



Assets	$	15,745
Property, plant and equipment	3,624
Acquired identifiable intangible assets:
Trademarks (one to fifteen year useful lives)	7,100
Existing technology (thirteen year useful life)	12,600
Customer relationships (eleven year useful life)	33,500
Goodwill	135,349
Liabilities assumed	(20,330		)
Total	$	187,588

Pro Forma Financial Information

The pro forma financial information is presented for informational purposes only and is not indicative of the results of operations that would have been achieved if the acquisition had taken place at the beginning of January 1, 2011 or results that may occur in the future (in thousands):



	Year Ended December 31,
	2011
Net revenues	$	492,468
Net income	$	62,116

Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2013

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The change in the carrying value of goodwill for the year ended December 31, 2013 by our reportable segments, which are also our reporting units, are as follows (in thousands):



	Clear Aligner			Scanners and CAD/CAM Services			Total
Balance as of December 31, 2011	$	58,445		$	76,938		$	135,383
Adjustment to goodwill ¹	98			346			444
Impairment of goodwill	—			(36,591		)	(36,591		)
Balance as of December 31, 2012	58,543			40,693			99,236
Goodwill from ICA acquisition	3,558			—			3,558
Impairment of goodwill	—			(40,693		)	(40,693		)
Adjustments ²	(478		)	—			(478		)
Balance as of December 31, 2013	$	61,623		$	—		$	61,623


²	The adjustments to goodwill during 2013 were a result of foreign currency translation.

Schedule Of Amortized Intangible Assets

ntangible assets arising either as a direct result from the Cadent acquisition or individually acquired are being amortized as follows (in thousands):



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2013		Accumulated Amortization			Impairment Charge			Net Carrying Value as of December 31, 2013
Trademarks	15	$	7,100	$	(1,100	)	$	(4,179	)	$	1,821
Existing technology	13	12,600		(2,236		)	(4,328		)	6,036
Customer relationships	11	33,500		(7,112		)	(10,751		)	15,637
Other	8	285		(40		)	—			245
Total Intangible Assets		$	53,485	$	(10,488	)	$	(19,258	)	$	23,739



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2012		Accumulated Amortization			Net Carrying Value as of December 31, 2012
Trademarks	15	$	7,100	$	(895	)	$	6,205
Existing technology	13	12,600		(1,642		)	10,958
Customer relationships	11	33,500		(5,002		)	28,498
Other	8	125		(9		)	116
Total Intangible Assets		$	53,325	$	(7,548	)	$	45,777

Schedule of Future Amortization For Finited-Lived Intangible Assets

The total estimated annual future amortization expense for these acquired intangible assets as of December 31, 2013 is as follows (in thousands):



Fiscal Year
2014	$	3,053
2015	2,600
2016	2,600
2017	2,600
2018	2,600
Thereafter	10,286
Total	$	23,739

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2013

Stock-based Compensation Expense

The stock-based compensation related to all of our stock-based awards and employee stock purchases for the year ended December 31, 2013, 2012 and 2011 is as follows (in thousands):



	For the Year Ended December 31,
	2013		2012		2011
Cost of net revenues	$	2,565	$	1,843	$	1,818
Sales and marketing	7,093		5,581		5,495
General and administrative	13,261		10,361		9,096
Research and development	3,519		3,698		2,756
Total stock-based compensation	$	26,438	$	21,483	$	19,165

Stock Option Activity

Activity for the year ended December 31, 2013, under the stock option plans are set forth below (in thousands, except years and per share amounts):



	Stock Options
	Number of Shares Underlying Stock Options		Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (in years )	Aggregate Intrinsic Value
Outstanding as of December 31, 2012	3,276		15.21
Granted	—		—
Exercised	(1,863	)	14.57
Cancelled or expired	(92	)	15.35
Outstanding as of December 31, 2013	1,321		$	16.08	3.61	$	54,231
Vested and expected to vest at December 31, 2013	1,317		$	16.06	3.61	$	54,102
Exercisable at December 31, 2013	1,205		$	15.65	3.59	$	49,996

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Method Used

The following weighted-average assumptions used in the Monte Carlo simulation were as follows:



	Year Ended December 31,
	2013			2012			2011
Expected term (in years)	3			3			3
Expected volatility	47.0		%	54.0		%	58.4		%
Risk-free interest rate	0.4		%	0.4		%	1.3		%
Expected dividends	—			—			—
Weighted average fair value per share at grant date	$	35.49		$	29.45		$	22.12

2001 Purchase Plan

Weighted Average Assumptions Used for the Fair Value of Options Component of Purchase Plan Granted Estimated at Grant Date

The fair value of the option component of the Purchase Plan shares was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:



	December 31,
	2013			2012			2011
Employee Stock Purchase Plan:
Expected term (in years)	1.2			1.2			1.5
Expected volatility	44.9		%	49.7		%	43.2		%
Risk-free interest rate	0.2		%	0.2		%	0.4		%
Expected dividends	—			—			—
Weighted average fair value at grant date	$	11.69		$	11.10		$	7.29

Stock Option

Weighted Average Assumptions Used for the Fair Value of Options Component of Purchase Plan Granted Estimated at Grant Date

The fair value of stock options granted was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:



	2013			2012			2011
Stock options ¹:
Expected term (in years)	—			—			4.4
Expected volatility	—		%	—		%	60.6		%
Risk-free interest rate	—		%	—		%	1.7		%
Expected dividends	—			—			—
Weighted average fair value at grant date	$	—		$	—		$	10.87

Restricted Stock Units (RSUs)

Summary Of Nonvested Shares

A summary for the year ended December 31, 2013, is as follows (in thousands, except years and per share amounts):



	Shares Underlying RSUs		Average Grant Date Fair Value Price per Share		Weighted Remaining Vesting Period (in years)	Aggregate Intrinsic Value
Nonvested as of December 31, 2012	1,500		$	23.95
Granted	1,289		36.38
Vested and released	(573	)	22.90
Forfeited	(172	)	26.37
Nonvested as of December 31, 2013	2,044		$	31.88	1.44	$	116,818

Market Performance Based Restricted Stock Units

Summary Of Nonvested Shares

The following table summarizes the MSU performance as of December 31, 2013:



	Number of Shares Underlying MSUs (in thousands)		Weighted Average Remaining Vesting Period (in years )	Aggregate Intrinsic Value (in thousands)
Nonvested as of December 31, 2012	266
Granted	225
Vested and released	(96	)
Forfeited	(88	)
Nonvested as of December 31, 2013	307		1.57	$	17,556

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2013

Income Tax Disclosure [Abstract]

Schedule of Income before Income Tax, Domestic and Foreign

Income before provision for income taxes consisted of the following (in thousands):



	Year ended December 31,
	2013		2012		2011
Domestic	$	31,993	$	32,341	$	52,184
Foreign	61,146		51,955		37,757
Total Income before provision for income taxes	$	93,139	$	84,296	$	89,941

Schedule of Components of Income Tax Expense (Benefit)

The provision for income taxes consisted of the following (in thousands):



	Year Ended December 31,
	2013			2012		2011
Federal
Current	$	26		$	—	$	65
Deferred	24,262			22,382		21,026
	24,288			22,382		21,091
State
Current	1,235			438		224
Deferred	1,158			1,486		1,394
	2,393			1,924		1,618
Foreign
Current	3,113			1,173		1,263
Deferred	(950		)	126		(747		)
	2,163			1,299		516
Provision for income taxes	$	28,844		$	25,605	$	23,225

Schedule of Effective Income Tax Rate Reconciliation

The differences between income taxes using the federal statutory income tax rate of 35% and our effective tax rate were as follows:



	Year Ended December 31,
	2013		2012		2011
U.S. federal statutory income tax rate	35.00	%	35.00	%	35.00	%
State income taxes, net of federal tax benefit	2.54		2.36		1.58
Impact of differences in foreign tax rates	(20.41	)	(20.00	)	(14.99	)
Goodwill Impairment	15.29		15.19		—
Stock-based compensation	0.47		(1.15	)	1.67
Non-deductible transaction fees	—		—		1.29
Valuation allowance release	—		—		(0.14	)
Other items not individually material	(1.92	)	(1.02	)	1.41
	30.97	%	30.38	%	25.82	%

Schedule of Deferred Tax Assets and Liabilities

As of December 31, 2013 and December 31, 2012, the significant components of our deferred tax assets and liabilities were (in thousands):



	Year Ended December 31,
	2013			2012
Deferred tax assets:
Net operating loss and capital loss carryforwards	$	39,978		$	37,183
Credit carryforwards	9,362			8,806
Reserves and accruals	26,729			19,703
Translation gains	48			43
Stock-based compensation	9,100			9,908
	85,217			75,643
Deferred tax liabilities:
Prepaid expenses	557			345
Depreciation and amortization	5,320			9,903
	5,877			10,248
Net deferred tax assets before valuation allowance	79,340			65,395
Valuation allowance	(35,108		)	(27,056		)
Net deferred tax assets	$	44,232		$	38,339

Schedule of Unrecognized Tax Benefits Rollforward

The changes in the balance of gross unrecognized tax benefits, which exclude interest and penalties, for fiscal year ended December 31, 2013, 2012, and 2011, is as follows (in thousands):



Unrecognized tax benefit as of December 31, 2011	$	15,472
Tax positions related to current year:
Additions for uncertain tax positions	5,087
Tax positions related to prior year:
Additions for uncertain tax positions	80
Unrecognized tax benefit as of December 31, 2012	20,639
Tax positions related to current year:
Additions for uncertain tax positions	6,110
Tax positions related to prior year:
Decreases for uncertain tax positions	(81		)
Unrecognized tax benefit as of December 31, 2013	$	26,668

Segments and Geographical Information (Tables)

12 Months Ended

Dec. 31, 2013

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment



	For the Year Ended December 31,
Net Revenues	2013		2012		2011
Clear Aligner
Invisalign Full	$	382,054	$	338,600	$	302,391
Invisalign Express/Lite	72,418		51,486		42,509
Invisalign Teen	84,850		67,127		54,529
Invisalign Assist	30,603		28,705		27,527
Invisalign non-case revenues	44,724		30,663		24,757

SCCS
Scanners	23,698		20,059		13,383
CAD/CAM Services	21,859		23,401		14,645
Total net revenues	$	660,206	$	560,041	$	479,741

Gross Profit
Clear Aligner	$	484,835	$	405,970	$	354,700
SCCS	13,271		10,418		6,583
Total gross profit	$	498,106	$	416,388	$	361,283

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas

Net revenues and long-lived assets are presented below by geographic area (in thousands):



	For the Year Ended December 31,
	2013		2012		2011
Net revenues ¹:
United States	$	491,410	$	427,929	$	359,936
the Netherlands	127,769		105,942		97,910
Other international	41,027		26,170		21,895
Total net revenues	$	660,206	$	560,041	$	479,741



	As of December 31,
	2013		2012		2011
Long-lived assets ²:
United States	$	61,439	$	60,098	$	43,868
Mexico	6,291		6,473		4,673
the Netherlands	1,630		1,383		343
Other international	6,383		11,237		5,081
Total long-lived assets	$	75,743	$	79,191	$	53,965


¹	Net revenues are attributed to countries based on location of where revenue is recognized.


²	Long-lived assets are attributed to countries based on entity that owns the assets.

Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.

+ References+ Details

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 financial_institution segment	Dec. 31, 2012	Dec. 31, 2011
Significant Accounting Policies [Line Items]
Number of operating segments	2
Original maturity of highly liquid investments included in Cash and cash equivalents	2 years
Number of financial instutions used	2
Scanners, Warranty period	1 year
Advertising cost	$ 26.0	$ 23.6	$ 21.2
Lease term	9 years
Undistributed earnings of foreign subsidiaries	186.4
Medical device tax expense	7.1
Building
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	20 years
Software Development
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	3 years
Minimum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	3 years
Other intangible assets, estimated useful lives	1 year
Maximum
Significant Accounting Policies [Line Items]
Original maturity of highly liquid investments included in Cash and cash equivalents	3 months
Property, plant and equipment, estimated useful life	10 years
Other intangible assets, estimated useful lives	15 years
Maximum \| Leasehold improvements
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	5 years
Noncurrent Assets [Member]
Significant Accounting Policies [Line Items]
Restricted cash	4.0	4.0
Prepaid Expenses and Other Current Assets [Member]
Significant Accounting Policies [Line Items]
Restricted cash	$ 1.6	$ 1.6

Summary of Significant Accounting Policies - Out of period adjustment (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Provision for income taxes

$ (660,206)

^[1]

$ (560,041)

^[1]

$ (479,741)

^[1]

Operating expenses

403,894

330,796

270,923

28,844

25,605

23,225

Net income

64,295

58,691

66,716

Restatement Adjustment [Member]

Provision for income taxes

1,700

Operating expenses

(700)

500

Net income

$ 1,900

[1]	Net revenues are attributed to countries based on location of where revenue is recognized.2 Long-lived assets are attributed to countries based on entity that owns the assets.

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ Details

Marketable Securities and Fair Value Measurements - Short-term and Long-term Securities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 126,992	$ 28,473
Gross Unrealized Gains	55	17
Gross Unrealized Losses	(7)	(5)
Fair Value	127,040	28,485
Short-term Investments \| Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	54,318	4,646
Gross Unrealized Gains	10	1
Gross Unrealized Losses	0	0
Fair Value	54,328	4,647
Short-term Investments \| Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	29,079	18,767
Gross Unrealized Gains	10	7
Gross Unrealized Losses	(4)	(4)
Fair Value	29,085	18,770
Short-term Investments \| U.S. dollar dominated foreign corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	13,959	5,060
Gross Unrealized Gains	12	9
Gross Unrealized Losses	0	(1)
Fair Value	13,971	5,068
Short-term Investments \| Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,006
Gross Unrealized Gains	11
Gross Unrealized Losses	(3)
Fair Value	7,014
Short-term Investments \| U.S. government agency bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	16,693
Gross Unrealized Gains	10
Gross Unrealized Losses	0
Fair Value	16,703
Short-term Investments \| Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,937
Gross Unrealized Gains	2
Gross Unrealized Losses	0
Fair Value	5,939
Long Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	101,973	21,239
Gross Unrealized Gains	62	21
Gross Unrealized Losses	(57)	(8)
Fair Value	101,978	21,252
Long Term Investments \| Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	23,308	16,132
Gross Unrealized Gains	14	16
Gross Unrealized Losses	(9)	(7)
Fair Value	23,313	16,141
Long Term Investments \| U.S. dollar dominated foreign corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	19,485	3,038
Gross Unrealized Gains	27	4
Gross Unrealized Losses	(17)	(1)
Fair Value	19,495	3,041
Long Term Investments \| Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,326
Gross Unrealized Gains	13
Gross Unrealized Losses	(8)
Fair Value	8,331
Long Term Investments \| Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,800
Gross Unrealized Gains	4
Gross Unrealized Losses	(2)
Fair Value	5,802
Long Term Investments \| US Government Agency Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	38,138	2,069
Gross Unrealized Gains	1	1
Gross Unrealized Losses	(21)	0
Fair Value	38,118	2,070
Long Term Investments \| U.S. Government Treasury Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,916
Gross Unrealized Gains	3
Gross Unrealized Losses	0
Fair Value	$ 6,919

Marketable Securities and Fair Value Measurements - Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Investments, All Other Investments [Abstract]
One year or less	$ 127,040	$ 28,485
One year through two years	101,978	21,252
Marketable Securities	$ 229,018	$ 49,737

Marketable Securities and Fair Value Measurements - Fair Value Measured On A Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	$ 127,040	$ 28,485
Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	101,978	21,252
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	390,149	139,071
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	150,459	86,166
Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	239,690	52,905
Money market funds \| Fair Value, Measurements, Recurring \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market funds	143,540	86,166
Money market funds \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market funds	143,540	86,166
Money market funds \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market funds	0	0
Commercial paper \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	54,328	4,647
Commercial paper \| Fair Value, Measurements, Recurring \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market funds	15,398	950
Commercial paper \| Fair Value, Measurements, Recurring \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	54,328	4,647
Commercial paper \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market funds	0	0
Commercial paper \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Commercial paper \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market funds	15,398	950
Commercial paper \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	54,328	4,647
Corporate bonds \| Fair Value, Measurements, Recurring \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	29,085	18,770
Corporate bonds \| Fair Value, Measurements, Recurring \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	23,313	16,141
Corporate bonds \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Corporate bonds \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Corporate bonds \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	29,085	18,770
Corporate bonds \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	23,313	16,141
U.S. dollar dominated foreign corporate bonds \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	13,971	5,068
U.S. dollar dominated foreign corporate bonds \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	19,495	3,041
U.S. dollar dominated foreign corporate bonds \| Fair Value, Measurements, Recurring \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	13,971	5,068
U.S. dollar dominated foreign corporate bonds \| Fair Value, Measurements, Recurring \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	19,495	3,041
U.S. dollar dominated foreign corporate bonds \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
U.S. dollar dominated foreign corporate bonds \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
U.S. dollar dominated foreign corporate bonds \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	13,971	5,068
U.S. dollar dominated foreign corporate bonds \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	19,495	3,041
U.S. government agency bonds \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	16,703
U.S. government agency bonds \| Fair Value, Measurements, Recurring \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	16,703
U.S. government agency bonds \| Fair Value, Measurements, Recurring \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	38,118	2,070
U.S. government agency bonds \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0
U.S. government agency bonds \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
U.S. government agency bonds \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	16,704
U.S. government agency bonds \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	38,118	2,070
Israeli funds \| Fair Value, Measurements, Recurring \| Other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other assets	2,193	2,218
Israeli funds \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other assets	0	0
Israeli funds \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other assets	2,193	2,218
Municipal Securities [Member] \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	7,014
Municipal Securities [Member] \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	8,331
Municipal Securities [Member] \| Fair Value, Measurements, Recurring \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	7,014
Municipal Securities [Member] \| Fair Value, Measurements, Recurring \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	8,331
Municipal Securities [Member] \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0
Municipal Securities [Member] \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0
Municipal Securities [Member] \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	7,014
Municipal Securities [Member] \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	8,331
Asset-backed Securities [Member] \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	5,939
Asset-backed Securities [Member] \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	5,802
Asset-backed Securities [Member] \| Fair Value, Measurements, Recurring \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	5,939
Asset-backed Securities [Member] \| Fair Value, Measurements, Recurring \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	5,802
Asset-backed Securities [Member] \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0
Asset-backed Securities [Member] \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0
Asset-backed Securities [Member] \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	5,938
Asset-backed Securities [Member] \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	5,802
U.S. Government Treasury Bonds [Member] \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	6,919
U.S. Government Treasury Bonds [Member] \| Fair Value, Measurements, Recurring \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	6,919
U.S. Government Treasury Bonds [Member] \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	6,919
U.S. Government Treasury Bonds [Member] \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2) \| Long Term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	$ 0

Marketable Securities and Fair Value Measurements - Narrative (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended			3 Months Ended			6 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2013 Scanners and CAD/CAM Services	Dec. 31, 2012 Scanners and CAD/CAM Services	Sep. 30, 2012 Scanners and CAD/CAM Services	Dec. 31, 2012 Scanners and CAD/CAM Services	Dec. 31, 2013 Scanners and CAD/CAM Services	Dec. 31, 2012 Scanners and CAD/CAM Services
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Original maturity of highly liquid investments included in Cash and cash equivalents	2 years
Weighted average maturity		10 months
Impairment of long lived assets	$ 26,320	$ 0	$ 0	$ 7,000
Impairment of goodwill	$ 40,693	$ 36,591	$ 0	$ 40,700	$ 11,900	$ 24,700	$ 36,600	$ 40,693	$ 36,591

Goodwill, Translation Adjustments

The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

+ References+ Details

Balance Sheet Components - Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 5,172	$ 7,629
Work in process	4,241	3,889
Finished goods	4,555	3,604
Inventories	$ 13,968	$ 15,122

Balance Sheet Components - Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property and equipment	$ 181,249	$ 165,126
Less: Accumulated depreciation and amortization	(105,506)	(85,935)
Property, plant and equipment, net	75,743	79,191
Clinical and manufacturing equipment
Property, Plant and Equipment [Line Items]
Property and equipment	104,373	83,821
Computer hardware
Property, Plant and Equipment [Line Items]
Property and equipment	24,851	22,706
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment	21,286	20,346
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment	7,275	6,808
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	14,996	12,388
Building
Property, Plant and Equipment [Line Items]
Property and equipment	1,868	1,868
Land
Property, Plant and Equipment [Line Items]
Property and equipment	1,162	1,162
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment	$ 5,438	$ 16,027

Balance Sheet Components - Accrued Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Balance Sheet Related Disclosures [Abstract]
Accrued payroll and benefits	$ 43,029	$ 39,621
Accrued sales rebate	10,100	8,333
Accrued sales tax and value added tax	6,215	5,253
Accrued sales and marketing expenses	3,893	4,088
Accrued warranty	3,104	4,050
Accrued accounts payable	2,764	2,866
Accrued professional fees	1,892	2,349
Accrued income taxes	1,205	572
Other	8,143	7,115
Total current accrued liabilities	$ 80,345	$ 74,247

Balance Sheet Components - Warranty Accrual Activity (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 4,050	$ 3,177
Charged to cost of revenues	2,850	4,637
Actual warranty expenditures	(3,796)	(3,764)
Balance at end of period	$ 3,104	$ 4,050

Balance Sheet Components - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization	$ 13,887	$ 13,440	$ 12,112
Scanners, Warranty period	1 year

Business Combinations - Additional Information (Detail) (USD $)	12 Months Ended				3 Months Ended			6 Months Ended	12 Months Ended						0 Months Ended	8 Months Ended	12 Months Ended						0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Apr. 29, 2011	Mar. 31, 2013 Scanners and CAD/CAM Services	Dec. 31, 2012 Scanners and CAD/CAM Services	Sep. 30, 2012 Scanners and CAD/CAM Services	Dec. 31, 2012 Scanners and CAD/CAM Services	Dec. 31, 2013 Scanners and CAD/CAM Services	Dec. 31, 2012 Scanners and CAD/CAM Services	Dec. 31, 2011 Scanners and CAD/CAM Services	Dec. 31, 2013 Clear Aligner	Dec. 31, 2012 Clear Aligner	Dec. 31, 2011 Clear Aligner	Apr. 29, 2013 Cadent [Member]	Dec. 31, 2011 Cadent [Member]	Dec. 31, 2013 Cadent [Member]	Dec. 31, 2012 Cadent [Member]	Jul. 31, 2011 Cadent [Member]	Apr. 29, 2011 Cadent [Member]	Apr. 29, 2011 Cadent [Member] Scanners and CAD/CAM Services	Apr. 29, 2011 Cadent [Member] Clear Aligner	Apr. 29, 2013 ICA Holdings Pty Limited [Member]	Apr. 30, 2013 ICA Holdings Pty Limited [Member]
Business Acquisition [Line Items]
Acquisition, net of cash acquired	$ 7,652,000	$ 0	$ 187,588,000												$ 187,600,000								$ 8,600,000
Transaction costs																			6,400,000
Goodwill	61,623,000	99,236,000	135,383,000	135,349,000		40,693,000		40,693,000	0	40,693,000	76,938,000	61,623,000	58,543,000	58,445,000						135,300,000	77,300,000	58,000,000		3,600,000
Impairment of goodwill	40,693,000	36,591,000	0		40,700,000	11,900,000	24,700,000	36,600,000	40,693,000	36,591,000		0	0
Contributed revenues																28,000,000	45,600,000	43,500,000
Gross profit	498,106,000	416,388,000	361,283,000						13,271,000	10,418,000	6,583,000	484,835,000	405,970,000	354,700,000
Contributed gross profit																6,500,000	10,400,000
Assets acquired																								7,400,000
Liabilities assumed				$ 20,330,000																				$ 2,400,000

Business Combinations - Summary of Allocation of the Preliminary Purchase Price (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Apr. 29, 2011
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Assets				$ 15,745
Property, plant and equipment				3,624
Goodwill	61,623	99,236	135,383	135,349
Liabilities assumed				(20,330)
Total				187,588
Trademarks (one to fifteen year useful lives)
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Acquired identifiable intangible assets				7,100
Existing technology (thirteen year useful life)
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Acquired identifiable intangible assets				12,600
Customer relationships (eleven year useful life)
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Acquired identifiable intangible assets				$ 33,500

Business Combinations - Summary of Allocation of the Preliminary Purchase Price (Parenthetical) (Detail)	0 Months Ended	12 Months Ended
	Apr. 29, 2011	Dec. 31, 2013	Dec. 31, 2012
Trademarks
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Estimated useful lives of intangibles		15 years	15 years
Existing technology
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Estimated useful lives of intangibles	13 years	13 years	13 years
Customer Relationships [Member]
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Estimated useful lives of intangibles	11 years	11 years	11 years
Minimum
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Estimated useful lives of intangibles		1 year
Minimum \| Trademarks
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Estimated useful lives of intangibles	1 year
Maximum
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Estimated useful lives of intangibles		15 years
Maximum \| Trademarks
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Estimated useful lives of intangibles	15 years

Business Combinations - Results of Align and Cadent, on a Pro Forma Basis, as though the Companies Had Been Combined (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Business Combinations [Abstract]
Net revenues	$ 492,468
Net income	$ 62,116

Goodwill and Intangible Assets - Change in the Carrying Value of Goodwill (Detail) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Apr. 29, 2011

Dec. 31, 2013

Clear Aligner

Dec. 31, 2012

Clear Aligner

Mar. 31, 2013

Scanners and CAD/CAM Services

Dec. 31, 2012

Scanners and CAD/CAM Services

Sep. 30, 2012

Scanners and CAD/CAM Services

Dec. 31, 2012

Scanners and CAD/CAM Services

Dec. 31, 2013

Scanners and CAD/CAM Services

Dec. 31, 2012

Scanners and CAD/CAM Services

Goodwill [Line Items]

$ (478)

^[1]

$ (478)

^[1]

$ 0

^[1]

Goodwill [Roll Forward]

Balance, Beginning Balance

99,236

135,383

135,349

58,543

58,445

40,693

76,938

Adjustment to goodwill

3,558

444

^[2]

3,558

^[2]

346

^[2]

Impairment of goodwill

(40,693)

(36,591)

(40,700)

(11,900)

(24,700)

(36,600)

(40,693)

(36,591)

Balance, Ending Balance

$ 61,623

$ 99,236

$ 135,383

$ 135,349

$ 61,623

$ 58,543

$ 40,693

$ 0

$ 40,693

[1]

The adjustments to goodwill during 2013 were a result of foreign currency translation.

[2]

Goodwill and Intangible Assets - Intangible Assets as a Direct Result from the Cadent Acquisition (Detail) (USD $) In Thousands, unless otherwise specified	0 Months Ended	12 Months Ended
	Apr. 29, 2011	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount as of December 31, 2012		$ 53,485	$ 53,325
Accumulated Amortization		(10,488)	(7,548)
Impairment Charge		(19,258)
Total		23,739	45,777
Trademarks
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles		15 years	15 years
Gross Carrying Amount as of December 31, 2012		7,100	7,100
Accumulated Amortization		(1,100)	(895)
Impairment Charge		(4,179)
Total		1,821	6,205
Existing technology
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles	13 years	13 years	13 years
Gross Carrying Amount as of December 31, 2012		12,600	12,600
Accumulated Amortization		(2,236)	(1,642)
Impairment Charge		(4,328)
Total		6,036	10,958
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles	11 years	11 years	11 years
Gross Carrying Amount as of December 31, 2012		33,500	33,500
Accumulated Amortization		(7,112)	(5,002)
Impairment Charge		(10,751)
Total		15,637	28,498
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles		8 years	8 years
Gross Carrying Amount as of December 31, 2012		285	125
Accumulated Amortization		(40)	(9)
Impairment Charge		0
Total		$ 245	$ 116

Goodwill and Intangible Assets - Total Estimated Annual Future Amortization Expense for the Acquired Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
2014	$ 3,053
2015	2,600
2016	2,600
2017	2,600
2018	2,600
Thereafter	10,286
Total	$ 23,739	$ 45,777

Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended				1 Months Ended	3 Months Ended			6 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Apr. 29, 2011	Mar. 31, 2013 Scanners and CAD/CAM Services	Mar. 31, 2013 Scanners and CAD/CAM Services	Dec. 31, 2012 Scanners and CAD/CAM Services	Sep. 30, 2012 Scanners and CAD/CAM Services	Dec. 31, 2012 Scanners and CAD/CAM Services	Dec. 31, 2013 Scanners and CAD/CAM Services	Dec. 31, 2012 Scanners and CAD/CAM Services	Dec. 31, 2011 Scanners and CAD/CAM Services
Goodwill [Line Items]
Impairment of goodwill	$ 40,693,000	$ 36,591,000	$ 0			$ 40,700,000	$ 11,900,000	$ 24,700,000	$ 36,600,000	$ 40,693,000	$ 36,591,000
Goodwill	61,623,000	99,236,000	135,383,000	135,349,000			40,693,000		40,693,000	0	40,693,000	76,938,000
Asset impairment charges					26,300,000
Impairment of intangible assets					19,300,000
Impairment of long lived assets	$ 26,320,000	$ 0	$ 0			$ 7,000,000

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

+ References+ Details

Credit Facilities - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Mar. 22, 2013
Line of Credit Facility [Line Items]
Line of credit, available borrowings		$ 50,000,000
Current borrowing capacity		10,000,000
Minimum unrestricted cash balance requirement	50,000,000
Interest rate on borrowings at LIBOR plus, minimum	1.75%
Interest rate on borrowings at LIBOR plus, maximum	1.75%
Line of credit, amount outstanding	$ 0

Commitments and Contingencies - Minimum Future Lease Payments for Non-Cancelable Leases (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
2014	$ 7,878
2015	7,463
2016	6,708
2017	4,316
2018	1,483
Thereafter	425
Total minimum lease payments	$ 28,273

Stockholders' Equity - Additional Information (Detail) (USD $)	12 Months Ended							12 Months Ended									0 Months Ended			12 Months Ended
	Dec. 31, 2013 purchase_period	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Stockholder Rights Plan right	Dec. 31, 2013 Stockholder Rights Plan Minimum	Dec. 31, 2013 Incentive Plan 2005	Dec. 31, 2013 Amended And Restated 2005 Stock Incentive Plan	Dec. 31, 2013 2001 Purchase Plan	Dec. 31, 2013 Restricted Stock Units (RSUs)	Dec. 31, 2012 Restricted Stock Units (RSUs)	Dec. 31, 2011 Restricted Stock Units (RSUs)	Dec. 31, 2013 Stock Options	Dec. 31, 2013 Stock Options Incentive Plan 2005	Dec. 31, 2013 Market Performance Based Restricted Stock Units	Dec. 31, 2013 Market Performance Based Restricted Stock Units Minimum	Dec. 31, 2013 Market Performance Based Restricted Stock Units Maximum	May 16, 2013 Employee Stock Incentive Plan 2005 [Member]	Mar. 28, 2005 Shares Transferred From 2001 Stock Incentive Plan	Dec. 31, 2013 Shares Transferred From 2001 Stock Incentive Plan Amended And Restated 2005 Stock Incentive Plan	Dec. 31, 2013 Employee Stock Purchase Plan 2010	Dec. 31, 2012 Employee Stock Purchase Plan 2010	Dec. 31, 2011 Employee Stock Purchase Plan 2010	Dec. 31, 2013 Employee Stock Purchase Plan 2010 Maximum	Dec. 31, 2013 Employee Stock Purchase Plan	Dec. 31, 2012 Employee Stock Purchase Plan	Dec. 31, 2011 Employee Stock Purchase Plan	Dec. 31, 2013 Annual Vesting Stock Options Incentive Plan 2005	Dec. 31, 2013 Monthly Vesting Stock Options Incentive Plan 2005
Stockholders Equity Note [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights													25% vesting one year from the date of grant and 1/48th each month thereafter
Preferred stock purchase right, number of rights declared for each outstanding share of our common stock				1
Dividend distribution, date of record				Nov. 22, 2005
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001		$ 0.0001
Preferred stock purchase right, exercise price (usd per share)				37.00
Number of shares called by each right (shares)				0.001
Preferred stock purchase right, minimum ownership percentage that should be acquired or intended to be acquired to trigger exercise					15.00%
Ratio of common stock to purchase price				2
Preferred stock purchase right, expiration Date				November 22, 2015
Increase in shares available for grant (shares)																	7,000,000
Shares reserved for issuance						23,283,379	9,119,512												2,384,516
Stock incentive plan, term													7 years
Stock incentive plan, vesting period													4 years		2 years	3 years
Stock incentive plan, vesting percentage																											25.00%	2.08%
Total intrinsic value of stock options exercised	$ 46,700,000	$ 50,900,000	$ 23,700,000
Fair value of stock options vested	3,700,000	5,000,000	9,200,000
Total unamortized compensation cost									46,900,000			1,300,000		5,800,000										1,900,000
Weighted average period of total unamortized cost									2 years 7 months 6 days			10 months 24 days		1 year 7 months 6 days										7 months 6 days
Tax effect from exercised options												900,000
Restricted stock units, shares vested and released (shares)									572,815					95,502
Restricted stock units, shares withheld for tax payments									80,435					45,119
Restricted stock units, net issuance									492,380					50,383
Employees' taxes paid upon the vesting of restricted stock units	(4,363,000)	(2,106,000)	(1,897,000)
Total intrinsic value									20,300,000	12,500,000	8,900,000			3,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value									13,200,000	7,800,000	5,800,000			1,500,000
Percentage of market-performance based restricted stock units eligible to vest over the vesting period																150.00%
Employee Stock Purchase Plan, Duration Of Offering Period	24 months
Employee stock purchase plan, purchase price as percentage of fair market value of common stock								85.00%
Number of offering periods	4
Maximum number of shares available																							2,400,000
Employee stock purchase plan, shares issued																				288,675	336,382	482,542
Weighted average exercise price (usd per share)																				$ 21.96	$ 17.98	$ 10.63
Number of shares available for grant (shares)																	23,283,379			1,611,170
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period																		5,000,000
Stock-based compensation expense	$ 26,438,000	$ 21,483,000	$ 19,165,000																					$ 3,400,000	$ 2,000,000	$ 3,100,000

Stockholders' Equity - Stock-Based Awards and Employee Stock Purchases (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 26,438	$ 21,483	$ 19,165
Cost of revenues
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	2,565	1,843	1,818
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	7,093	5,581	5,495
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	13,261	10,361	9,096
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 3,519	$ 3,698	$ 2,756

Stockholders' Equity - Activity Under Stock Option Plans (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Number of Shares Underlying Stock Options
Outstanding beginning balance (shares)	3,276
Granted (shares)	0
Exercised (shares)	(1,863)
Cancelled or expired (shares)	(92)
Outstanding ending balance (shares)	1,321
Vested and expected to vest at December 31, 2013 (shares)	1,317
Exercisable at December 31, 2013 (shares)	1,205
Weighted Average Exercise Price per Share
Outstanding beginning balance (usd per share)	$ 15.21
Granted (usd per share)	$ 0.00
Exercised (usd per share)	$ 14.57
Cancelled or expired (usd per share)	$ 15.35
Outstanding ending balance (usd per share)	$ 16.08
Vested and expected to vest at December 31, 2013 (usd per share)	$ 16.06
Exercisable at December 31, 2013 (usd per share)	$ 15.65
Weighted Average Remaining Contractual Term (in years)
Outstanding as of December 31, 2013	3 years 7 months 10 days
Vested and expected to vest at December 31, 2013	3 years 7 months 10 days
Exercisable at December 31, 2013	3 years 7 months 2 days
Aggregate Intrinsic Value
Outstanding as of December 31, 2013	$ 54,231
Vested and expected to vest at December 31, 2013	54,102
Exercisable at December 31, 2013	$ 49,996

Stockholders' Equity - Weighted Average Assumptions Used for the Fair Value of Stock Options Granted Estimated at Grant Date Using Black-Scholes Option Pricing Model (Detail) (Stock Options, USD $)

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Stock Options

Expected term (in years)

0 years

^[1]

0 years

4 years 4 months 24 days

Expected volatility

0.00%

^[1]

0.00%

60.60%

Risk-free interest rate

0.00%

^[1]

0.00%

1.70%

Expected dividends

0.00%

^[1]

0.00%

Weighted average fair value at grant date (usd per share)

$ 0.00

^[1]

$ 0.00

$ 10.87

[1]	There were no stock options granted in 2013 or 2012.

Stockholders' Equity - Summary of Nonvested Shares (Detail) (Restricted Stock Units (RSUs), USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Restricted Stock Units (RSUs)
Shares Underlying RSUs
Nonvested beginning balance (shares)	1,500,000
Granted (shares)	1,289,000
Vested and released (shares)	(572,815)
Forfeited (shares)	(172,000)
Nonvested ending balance (shares)	2,044,000
Nonvested, beginning balance (usd per share)	$ 23.95
Granted (usd per share)	$ 36.38
Vested and released (usd per share)	$ 22.90
Forfeited (usd per share)	$ 26.37
Nonvested, ending balance (usd per share)	$ 31.88
Weighted Remaining Vesting Period (in years)
Nonvested as of December 31, 2013	1 year 5 months 9 days
Aggregate Intrinsic Value
Nonvested as of December 31, 2013	$ 116,818

Stockholders' Equity - Summary of MSU Performance (Detail) (Market Performance Based Restricted Stock Units, USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Market Performance Based Restricted Stock Units
Number of Shares
Nonvested beginning balance (shares)	266,000
Granted (shares)	225,000
Vested and released (shares)	(95,502)
Forfeited (shares)	(88,000)
Nonvested ending balance (shares)	307,000	266,000
Weighted Average Remaining Contractual Term
Nonvested	1 year 6 months 26 days
Aggregate Intrinsic Value
Nonvested	$ 17,556

Stockholders' Equity - Weighted-Average Assumptions Used in the Monte Carlo Simulation (Detail) (Market Performance Based Restricted Stock Units, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Market Performance Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	3 years	3 years	3 years
Expected volatility	47.00%	54.00%	58.40%
Risk-free interest rate	0.40%	0.40%	1.30%
Expected dividends	0.00%	0.00%	0.00%
Weighted average fair value per share at grant date (usd per share)	$ 35.49	$ 29.45	$ 22.12

Stockholders' Equity - Weighted Average Assumptions Used for the Fair Value of the Option Component of the Purchase Plan Shares Estimated at Grant Date Using Black-Scholes Option Pricing Model (Detail) (Employee Stock Purchase Plan, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	1 year 2 months 12 days	1 year 2 months 12 days	1 year 6 months
Expected volatility	44.90%	49.70%	43.20%
Risk-free interest rate	0.20%	0.20%	0.40%
Expected dividends	0.00%	0.00%	0.00%
Weighted average fair value at grant date (usd per share)	$ 11.69	$ 11.10	$ 7.29

Common Stock Repurchase Program - Additional Information (Detail) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	0 Months Ended	12 Months Ended
	Oct. 27, 2011	Dec. 31, 2013	Dec. 31, 2012
Share Repurchases [Line Items]
Repurchase of common stock, common stock authorized	$ 150,000,000
Common stock repurchased (in shares)		2.7	1.7
Repurchase of common stock, average price per share (usd per share)		$ 34.95	$ 27.28
Stock Repurchased and Retired During Period, Value		(95,107,000)	(47,203,000)
Additional Paid-in Capital
Share Repurchases [Line Items]
Stock Repurchased and Retired During Period, Value		(24,528,000)	(15,399,000)
Repurchase of common stock, aggregate purchase price - Increase/(Decrease) In Equity		(15,400,000)	(24,500,000)
Retained Earnings
Share Repurchases [Line Items]
Stock Repurchased and Retired During Period, Value		(70,579,000)	(31,804,000)
Repurchase of common stock, aggregate purchase price - Increase/(Decrease) In Equity		$ (31,800,000)	$ (70,600,000)

Employee Benefit Plans - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2009
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Accrued severance funds liability	$ 2.4	$ 2.7
Defined Contribution Pension Plan 401k
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer matching contribution as percentage of employee's salary deferral contributions				50.00%
Employer contributions amount	$ 2.1	$ 1.9	$ 1.8
Defined Contribution Pension Plan 401k \| Maximum
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer matching contribution as percentage of employee's eligible compensation				6.00%

Income Taxes - Domestic and Foreign Components of Income (loss) Before Provision for Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Domestic	$ 31,993	$ 32,341	$ 52,184
Foreign	61,146	51,955	37,757
Net income before provision for income taxes	$ 93,139	$ 84,296	$ 89,941

Income Taxes Income Taxes - Provision for (Benefit from) Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Federal
Current	$ 26	$ 0	$ 65
Deferred	24,262	22,382	21,026
Total federal income tax expense	24,288	22,382	21,091
State
Current	1,235	438	224
Deferred	1,158	1,486	1,394
Total state tax expense	2,393	1,924	1,618
Foreign
Current	3,113	1,173	1,263
Deferred	(950)	126	(747)
Total foreign tax expense	2,163	1,299	516
Provision for income taxes	$ 28,844	$ 25,605	$ 23,225

Income Taxes - Differences Between Income Taxes Using Federal Statutory Income Tax Rate and Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal tax benefit	2.54%	2.36%	1.58%
Impact of differences in foreign tax rates	(20.41%)	(20.00%)	(14.99%)
Goodwill Impairment	15.29%	15.19%	0.00%
Amortization of stock-based compensation	0.47%	(1.15%)	1.67%
Non-deductible transaction fees	0.00%	0.00%	1.29%
Valuation allowance release	0.00%	0.00%	(0.14%)
Other items not individually material	(1.92%)	(1.02%)	1.41%
Effective Income Tax Rate, Continuing Operations, Total	30.97%	30.38%	25.82%

Income Taxes Income Taxes - Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Net operating loss and capital loss carryforwards	$ 39,978	$ 37,183
Credit carryforwards	9,362	8,806
Reserves and accruals	26,729	19,703
Translation gains	48	43
Stock-based compensation	9,100	9,908
Total deferred tax assets, gross	85,217	75,643
Deferred tax liabilities:
Prepaid expenses	557	345
Depreciation and amortization	5,320	9,903
Total deferred tax liabilities, gross	5,877	10,248
Net deferred tax assets before valuation allowance	79,340	65,395
Valuation allowance	(35,108)	(27,056)
Net deferred tax assets	$ 44,232	$ 38,339

Income Taxes - Rollforward of Total Gross Unrecognized Tax Benefit (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefit as of beginning of period	$ 20,639	$ 15,472
Tax positions related to current year, additions for uncertain tax positions	6,110	5,087
Tax positions related to prior year, additions for uncertain tax positions		80
Decreases for uncertain tax positions	(81)
Unrecognized tax benefit as of end of period	$ 26,668	$ 20,639

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
Income Taxes - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2009
Income Taxes [Line Items]
Undistributed earnings of foreign subsidiaries	$ 186,400,000
Deferred tax assets, valuation allowance	35,108,000	27,056,000
Change in valuation allowance	8,000,000
Increase in unrecognized tax benefits	6,000,000
Unrecognized tax benefits	26,668,000	20,639,000	15,472,000
Acquisition Related Assets And Foreign Net Operating Loss Carryforwards [Member]
Income Taxes [Line Items]
Change in valuation allowance	9,800,000
Lapse In Statute Of Limitations [Member]
Income Taxes [Line Items]
Change in valuation allowance	1,800,000
Internal Revenue Service (IRS)
Income Taxes [Line Items]
Net operating loss carryforwards	42,400,000
Internal Revenue Service (IRS) \| Research
Income Taxes [Line Items]
Research credit carryforward	5,900,000
State and Local Jurisdiction
Income Taxes [Line Items]
Net operating loss carryforwards	56,700,000
State and Local Jurisdiction \| Research
Income Taxes [Line Items]
Research credit carryforward	3,600,000
Foreign Country
Income Taxes [Line Items]
Net operating loss carryforwards	36,700,000
Foreign Country \| Costa Rica
Income Taxes [Line Items]
Tax incentives, period				12 years
Tax incentives, corporate income tax rate that would apply absent the incentives	30.00%
Tax incentives, reduction in income taxes	27,700,000	21,800,000	15,400,000
Tax benefit of tax holiday on net income per share (diluted) (usd per share)	$ 0.34	$ 0.26	$ 0.19
Stock Options
Income Taxes [Line Items]
Net operating loss carryforwards	$ 25,200,000

Net Profit per Share - Computation of Basic and Diluted Net Profit Per Share Attributable to Common Stock (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Numerator:
Net income	$ 64,295	$ 58,691	$ 66,716
Denominator:
Weighted-average common shares outstanding, basic (shares)	80,551	80,529	77,988
Dilutive effect of potential common stock (shares)	2,038	2,511	2,306
Total shares, diluted (shares)	82,589	83,040	80,294
Net income per share, basic (usd per share)	$ 0.80	$ 0.73	$ 0.86
Net income per share, diluted (usd per share)	$ 0.78	$ 0.71	$ 0.83

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References+ Details

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References+ Details

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ Details

Net Profit per Share - Additional Information (Detail) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (shaares)	0.1	0.1	1.6

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References+ Details

Supplemental Cash Flow Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplemental Cash Flow Information [Abstract]
Taxes paid	$ 4,125	$ 2,825	$ 1,953
Non-cash investing and financing activities:
Fixed assets acquired with accounts payable or accrued liabilities	2,308	940	1,611
Unclaimed merger consideration liability	$ 0	$ 1,575	$ 0

Segments and Geographical Information Segments and Geographical Information - (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

$ 660,206

^[1]

$ 560,041

^[1]

$ 479,741

^[1]

498,106

416,388

361,283

Invisalign Full [Member]

382,054

338,600

302,391

Invisalign Express/Lite [Member]

72,418

51,486

42,509

Invisalign Teen [Member]

84,850

67,127

54,529

Invisalign Assist [Member]

30,603

28,705

27,527

Invisalign Non-Case Revenues [Member]

44,724

30,663

24,757

Scanners [Member]

23,698

20,059

13,383

CAD/CAM Services [Member]

21,859

23,401

14,645

Clear Aligner

484,835

405,970

354,700

Scanners and CAD/CAM Services

$ 13,271

$ 10,418

$ 6,583

[1]	Net revenues are attributed to countries based on location of where revenue is recognized.2 Long-lived assets are attributed to countries based on entity that owns the assets.

Segments and Geographical Information - Net Revenues by Geographic Area (Detail) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

$ 660,206

^[1]

$ 560,041

^[1]

$ 479,741

^[1]

United States

491,410

^[1]

427,929

^[1]

359,936

^[1]

the Netherlands

127,769

^[1]

105,942

^[1]

97,910

^[1]

Other international