^[1]

$ 1,079,874

$ 845,486

$ 761,653

Cost of net revenues

264,580

205,376

183,210

Selling, general and administrative

815,294

640,110

578,443

Operating expenses:

490,653

390,239

332,068

Research and development

75,720

61,237

52,799

Total operating expenses

566,373

451,476

384,867

Income from operations

248,921

188,634

193,576

Interest and other income (expense), net

(6,355)

(2,533)

(3,207)

Net income before provision for income taxes and equity in losses of investee

242,566

186,101

190,369

Provision for income taxes

51,200

42,081

44,537

Equity in losses of investee, net of tax

1,684

Net income

$ 189,682

$ 144,020

$ 145,832

Net income per share:

Basic (usd per share)

$ 2.38

$ 1.80

$ 1.81

Diluted (usd per share)

$ 2.33

$ 1.77

Shares used in computing net income per share:

Basic (shares)

79,856

79,998

80,754

Diluted (shares)

81,484

81,521

82,283

[1]	1) Long-lived assets are attributed to countries based on entity that owns the assets.(2) As a result of the new international corporate structure changes, approximately $92.0 million in long-lived assets were transferred from the U.S. to our Netherlands entity in 2016.

CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 189,682	$ 144,020	$ 145,832
Net change in foreign currency translation adjustment	(670)	(154)	(196)
Change in unrealized gains (losses) on investments, net of tax	712	(686)	(238)
Other comprehensive income (loss)	42	(840)	(434)
Comprehensive income	$ 189,724	$ 143,180	$ 145,398

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

Summary of Significant Accounting Policies

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 389,275	$ 167,714
Marketable securities, short-term	250,981	359,581
Accounts receivable, net of allowance for doubtful accounts and returns of $4,310 and $2,472, respectively	247,415	158,550
Inventories	27,131	19,465
Prepaid expenses and other current assets	38,176	26,700
Total current assets	952,978	732,010
Marketable securities, long-term	59,783	151,370
Property, plant and equipment, net	175,167	136,473
Equity method investments	45,061	0
Goodwill and intangible assets, net	81,998	79,162
Deferred tax assets	67,844	51,416
Other assets	13,320	8,202
Total assets	1,396,151	1,158,633
Current liabilities:
Accounts payable	28,596	34,354
Accrued liabilities	134,332	107,765
Deferred revenues	191,407	129,553
Total current liabilities	354,335	271,672
Income tax payable	45,133	37,512
Other long-term liabilities	1,294	1,523
Total liabilities	400,762	310,707
Commitments and contingencies (Notes 6 and 8)
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; 79,553 and 79,500 issued and outstanding, respectively)	8	8
Additional paid-in capital	864,871	821,507
Accumulated other comprehensive income (loss), net	(938)	(980)
Retained earnings	131,448	27,391
Total stockholders’ equity	995,389	847,926
Total liabilities and stockholders’ equity	$ 1,396,151	$ 1,158,633

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts and returns	$ 4,310	$ 2,472
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)	79,553	79,500
Common stock, outstanding (shares)	79,553	79,500

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss), Net	Retained Earnings (Deficit)
Beginning Balance (in shares) at Dec. 31, 2013		80,583
Beginning Balance at Dec. 31, 2013	$ 633,970	$ 8	$ 729,578	$ 294	$ (95,910)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	145,832				145,832
Net change in unrealized gains (losses) from investments	(238)			(238)
Net change in foreign currency translation adjustment	(196)			(196)
Issuance of common stock relating to employee equity compensation plans (in shares)		1,536
Issuance of common stock relating to employee equity compensation plans	18,028	$ 0	18,028
Tax withholdings related to net share settlement of restricted stock units	(7,608)		(7,608)
Common stock repurchased and retired (shares)		(1,914)
Common stock repurchased and retired	(98,233)		(17,804)		(80,429)
Net tax benefits from stock-based awards	21,393		21,393
Stock-based compensation	39,823		39,823
Ending Balance (in shares) at Dec. 31, 2014		80,205
Ending Balance at Dec. 31, 2014	752,771	$ 8	783,410	(140)	(30,507)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	144,020				144,020
Net change in unrealized gains (losses) from investments	(686)			(686)
Net change in foreign currency translation adjustment	(164)		(10)	(154)
Issuance of common stock relating to employee equity compensation plans (in shares)		991
Issuance of common stock relating to employee equity compensation plans	11,325	$ 0	11,325
Tax withholdings related to net share settlement of restricted stock units	(20,716)		(20,716)
Common stock repurchased and retired (shares)		(1,696)
Common stock repurchased and retired	(101,791)		(15,669)		(86,122)
Net tax benefits from stock-based awards	10,224		10,224
Stock-based compensation	52,943		52,943
Ending Balance (in shares) at Dec. 31, 2015		79,500
Ending Balance at Dec. 31, 2015	847,926	$ 8	821,507	(980)	27,391
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	189,682				189,682
Net change in unrealized gains (losses) from investments	712			712
Net change in foreign currency translation adjustment	(670)			(670)
Issuance of common stock relating to employee equity compensation plans (in shares)		1,163
Issuance of common stock relating to employee equity compensation plans	13,778		13,778
Tax withholdings related to net share settlement of restricted stock units	(29,857)		(29,857)
Common stock repurchased and retired (shares)		(1,110)
Common stock repurchased and retired	(96,218)		(10,593)		(85,625)
Net tax benefits from stock-based awards	15,888		15,888
Stock-based compensation	54,148		54,148
Ending Balance (in shares) at Dec. 31, 2016		79,553
Ending Balance at Dec. 31, 2016	$ 995,389	$ 8	$ 864,871	$ (938)	$ 131,448

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 189,682	$ 144,020	$ 145,832
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred taxes	(16,401)	(11,424)	4,088
Depreciation and amortization	24,002	18,004	17,856
Stock-based compensation	54,148	52,943	39,823
Net tax benefits from stock-based awards	15,888	10,224	21,393
Excess tax benefit from share-based payment arrangements	(16,773)	(10,396)	(21,393)
Equity in losses of investee	1,684	0	0
Other non-cash operating activities	12,031	13,799	10,106
Changes in assets and liabilities:
Accounts receivable	(94,444)	(40,775)	(27,229)
Inventories	(7,663)	(3,563)	(1,999)
Prepaid expenses and other assets	(9,390)	(3,726)	(2,924)
Accounts payable	(3,395)	7,575	2,887
Accrued and other long-term liabilities	37,629	19,462	22,692
Deferred revenues	60,656	41,854	15,767
Net cash provided by operating activities	247,654	237,997	226,899
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(70,576)	(53,451)	(24,092)
Purchase of marketable securities	(405,612)	(447,092)	(437,152)
Proceeds from maturities of marketable securities	387,873	304,125	176,810
Purchase of equity method investments	(46,745)	0	0
Proceeds from sales of marketable securities	216,119	30,011	82,990
Other investing activities	(8,211)	46	(183)
Net cash provided by (used in) investing activities	72,848	(166,361)	(201,627)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	13,778	11,325	18,028
Common stock repurchases	(96,218)	(101,791)	(98,233)
Excess tax benefit from share-based payment arrangements	16,773	10,396	21,393
Employees’ taxes paid upon the vesting of restricted stock units	(29,857)	(20,716)	(7,608)
Net cash used in financing activities	(95,524)	(100,786)	(66,420)
Effect of foreign exchange rate changes on cash and cash equivalents	(3,417)	(3,007)	(1,934)
Net increase (decrease) in cash and cash equivalents	221,561	(32,157)	(43,082)
Cash and cash equivalents, beginning of year	167,714	199,871	242,953
Cash and cash equivalents, end of year	$ 389,275	$ 167,714	$ 199,871

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2016

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 is located in Amsterdam, the Netherlands. We have two operating segments: (1) Clear Aligner, known as the Invisalign System, and (2) Scanners and Services ("Scanner"), known as the iTero intraoral 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.

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 2014, we recorded an out of period correction that resulted in an increase in the provision for income taxes of $1.8 million. We do not believe the decrease to net income related to the out of period adjustment is material to the consolidated financial statements for the fiscal year ended December 31, 2014 or to any prior years' consolidated financial statements.

Use of Estimates

The preparation of financial statements in conformity with generally accepted accounting principles ("GAAP") 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, long-lived assets and goodwill, equity method investments, useful lives of intangible assets and property and equipment, revenue recognition, stock-based compensation, equity losses of investee, 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

We measure our cash equivalents, marketable securities, Israeli fund and long-term notes receivable 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 or remaining 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, 2016 was $3.7 million, of which $3.3 million was classified as a long-term asset and $0.4 million as a current asset. Our restricted cash balance as of December 31, 2015 was $3.5 million, of which $3.3 million was classified as a long-term asset and $0.2 million as a current asset. The restricted cash primarily consisted of funds reserved for legal requirements.

Marketable Securities

We invest primarily in money market funds, commercial paper, corporate bonds, U.S. government agency bonds, asset-backed securities, municipal securities, U.S. government treasury bonds and certificates of deposits.

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), net 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 interest and other income (expense), net as incurred. We periodically evaluate these investments for other-than-temporary impairment.

Variable Interest Entities

We have interests in entities determined to be variable interest entity (“VIE”). If we determine we are the primary beneficiary of a VIE, we would consolidate the VIE into our financial statements. In determining if we are the primary beneficiary, we evaluate whether we have the power to direct the activities that most significantly impact the VIE's economic performance and the obligation to absorb losses or the right to receive benefits of the VIE that could potentially be significant to the VIE. Our evaluation includes identification of significant activities and an assessment of our ability to direct those activities based on governance provisions and arrangements to provide or receive product and process technology, product supply, operations services, equity funding, financing, and other applicable agreements and circumstances. Our assessments of whether we are the primary beneficiary of a VIE require significant assumptions and judgments. We have concluded that we are not the primary beneficiary of our VIE investments; therefore, we do not consolidate their results into our consolidated financials.

Investments in Privately Held Companies

Investments in privately held companies in which we can exercise significant influence but do not own a majority equity interest or otherwise control, are accounted for under the equity method of accounting. Equity method investments are reported on our balance sheet as a single amount, and we record our share of their operating results within equity in losses of investee, net of tax in our Consolidated Statement of Operations.

Derivative Financial Instruments

We may enter into foreign currency forward contracts to minimize the short-term impact of foreign currency exchange rate fluctuations associated with certain assets and liabilities. These forward contracts are not designated as hedging instruments and do not subject us to material balance sheet risk due to fluctuations in foreign currency exchange rates. The gains and losses on these forward contracts are intended to offset the gains and losses in the underlying foreign currency denominated monetary assets and liabilities being economically hedged. We do not enter into foreign currency forward contracts for trading or speculative purposes. The net gain or loss from the settlement of these foreign currency forward contracts is recorded in interest and other income (expense), net in the Consolidated Statement of Operations.

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. For certain European and Asia Pacific subsidiaries where the local currency is the functional currency, adjustments from translating financial statements from the local currency to the U.S. dollar reporting currency are recorded as a separate component of accumulated other comprehensive income (loss), net in the stockholders’ equity section of the Consolidated Balance Sheet. 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, 2016 and 2015, there were no material amounts in accumulated other comprehensive income (loss), net related to the translation of our foreign subsidiaries’ financial statements. The foreign currency revaluation that are derived from monetary assets and liabilities stated in a currency other than functional currency are included in interest and other income (expense), net. For the year ended December 31, 2016 and 2015, we had foreign currency net losses of $8.0 million and $4.0 million, respectively.

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, commercial paper, corporate bonds, U.S. government agency bonds, asset-backed securities, municipal securities, U.S. government treasury bonds and certificates of deposits. 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 adversely affect 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, 2016 or 2015, or net revenues for the year ended December 31, 2016, 2015 or 2014.

We have certain credit risk under our Loan and Security Agreement ("Loan Agreement") with SmileDirectClub, LLC ("SDC"). We perform ongoing evaluation of credit worthiness of SDC. If the fair value of equity investment is deemed to be other-than temporary impaired, we will be required to write down the value of our investments, which could adversely affect our results of operations and financial condition (Refer to Note 8 "Commitments and Contingencies" of the Notes of Consolidated Financial Statements for more information on our Loan Agreement with SDC).

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 treatment 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 intraoral scanners at our facilities 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 Or Yehuda, 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 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. Construction in progress ("CIP") 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 expenses. Maintenance and repairs are expensed as incurred. Refer to Note 3 "Balance Sheet Components" of the Notes of Consolidated Financial Statements for details on estimated useful lives.

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. For the year ended December 31, 2016 and 2015, all goodwill is attributed to our Clear Aligner reporting unit.

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 ranging from 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 units 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. 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.

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. 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. 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 assumptions. The estimation of fair value utilizing a discounted cashflow 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. Refer to Note 5 "Goodwill and Intangible Assets" of the Notes of Consolidated Financial Statements for details on intangible long-lived assets.

There were no triggering events in 2016 that would cause impairments of our goodwill or long-lived assets.

Development Costs for Internal Use Software

Internally developed software includes enterprise-level business software that we customized to meet our specific operational needs. Such capitalized costs include external direct costs utilized in developing or obtaining the applications and payroll and payroll-related costs for employees, who are directly associated with the development of the applications. Internally developed software costs capitalized during the year ended December 31, 2016 and 2015 were $13.2 million and $25.4 million, respectively, related to our enterprise resource planning ("ERP") project which we placed into production during 2016 and amortize over 10 years.

The costs to develop software that is marketed externally have not been capitalized as we believe our current software development process is essentially completed concurrent with the establishment of technological feasibility. As such, all related software development costs are expensed as incurred and included in research and development expense in our Consolidated Statements of Operations.

Product Warranty

Clear Aligner

We warrant our Invisalign products against material defects until the aligner case is complete. We warrant SmileDirectClub, LLC (“SDC”) products against material defects for one year. 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.

Scanners and Services

We warrant our intraoral 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 allowances 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 allowances.

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 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, or on best estimated selling price (“BESP”) if neither VSOE or TPE exist.


•	VSOE - In most instances, this applies to products and services that are sold separately in stand-alone arrangements. We determine VSOE based on 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 does 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 our pricing practices. Adjustments for other market and company specific factors are made as deemed necessary in determining BESP. We regularly review our estimates of selling price and maintain internal controls over the establishment and update of these estimates.

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 have passed to customers based on the shipping terms, and allowances for discounts, returns, and customer incentives can be reliably estimated. Provisions for discounts and rebates to customers are provided for in the same period that the related product sales are recorded.

Clear Aligner

We enter into arrangements (“treatment plans”) that involve multiple future product deliverables. Invisalign Full, Invisalign Teen, and Invisalign Assist products ("Comprehensive Products") include optional additional aligners at no charge for a period of up to five years after initial shipment. Invisalign Teen also includes up to six optional replacement aligners in the price of the product and may be ordered by the dental professional any time throughout treatment. Invisalign Lite ("Non-Comprehensive Products") includes one optional case refinement in the price of the product. Case refinement is a finishing tool used to adjust a patient's teeth to the desired final position and may be elected by the dental professional at any time during treatment; however, it is generally ordered in the last stages of orthodontic treatment.

We determined that our treatment plans, except Invisalign Assist with progress tracking, comprise the following deliverables which also represent separate units of accounting: initial aligners, additional aligners, case refinement, 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 shipment of each unit in the treatment plan.

For Invisalign Assist with the progress tracking feature, aligners and services are provided to the dental professional every nine stages (“a batch”). We are 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.

Scanners and Services

We recognize revenues from the sales of iTero intraoral scanners and CAD/CAM services. CAD/CAM services include scanning services, extended warranty for the intraoral scanners, a range of iTero restorative services, and OrthoCAD services such as OrthoCAD iRecord. We sell intraoral scanners and services through both our direct sales force and distribution partners. The intraoral 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. When intraoral 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 and no significant obligations for installation or training remain. For certain distributors who provide installation and training to the customer, we recognize scanner revenue when the intraoral 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. 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 personnel-related costs including stock-based compensation and outside consulting expenses associated with the research and development of new products and enhancements to existing products and allocations of corporate overhead expenses including facilities and IT.

Advertising Costs

The cost of advertising and media is expensed as incurred. For the year ended December 31, 2016, 2015 and 2014, advertising costs totaled $36.0 million, $23.4 million and $26.9 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 repurchases 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 Sheet.

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 Statement of Operation 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, 2016 included historical operating profits and a projection of future income sufficient to realize most of our remaining deferred tax assets. As of December 31, 2016, 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, 2016, U.S. income taxes and foreign withholding taxes associated with the repatriation of undistributed earnings of foreign subsidiaries on a cumulative total of $438.0 million was not provided as 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 use the Black-Scholes option pricing model to determine the fair value of employee stock purchase plan shares. 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.

Comprehensive Income

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

Recent Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board ("FASB") released Accounting Standards Update ("ASU") 2014-9, "Revenue from Contracts with Customers," (Topic 606) to supersede nearly all existing revenue recognition guidance under GAAP. The core principle of the standard is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for the goods or services. The new standard defines a five step process to achieve this core principle and, in doing so, it is possible more judgment and estimates may be required within the revenue recognition process than required under existing GAAP including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. In addition, the new standard requires that reporting companies disclose the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. We are required to adopt this standard starting in the first quarter of fiscal year 2018 using either of two methods: (i) retrospective to each prior reporting period presented with the option to elect certain practical expedients as defined within the standard; or (ii) retrospective with the cumulative effect of initially applying the standard recognized at the date of initial application and providing certain additional disclosures as defined per the standard. We plan to adopt the standard in the first quarter of fiscal year 2018 by applying the full retrospective method. Our ability to adopt using the full retrospective method is dependent on the completion of our analysis of information necessary to restate prior period financial statements. We are continuing to assess the impact of the adoption of this update on our consolidated financial statements and related disclosures.

In April 2016, the FASB released ASU No. 2016-10, "Revenue from Contracts with Customers," to clarify the following two aspects of Topic 606: identifying performance obligations and the licensing implementation guidance, while retaining the principles for those areas of the ASU 2014-9 issued in May 2014. The effective date and the transition requirement of the amendments in this update are the same as the effective date and transition requirements of Topic 606.

In May 2016, the FASB released ASU No. 2016-12, "Revenue from Contracts with Customers," to address certain issues in the Topic 606 guidance on assessing the collectability, presentation of sales taxes, non-cash consideration, and completed contracts and contract modifications at transition. The ASU provides narrow-scope improvements and practical expedients to the ASU 2014-9 issued in May 2014. The effective date and the transition requirement of the amendments in this update are the same as the effective date and transition requirements of Topic 606.

In December 2016, the FASB released ASU No. 2016-20, "Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers," to clarify certain aspects of guidance in the Topic 606 including its scope, disclosure requirements and contract cost accounting, while retaining the principles for those areas of the ASU 2014-9 issued in May 2014. The effective date and the transition requirement of the amendments in this update are the same as the effective date and transition requirements of Topic 606.

In February 2016, the FASB issued ASU No. 2016-02, “Leases” (Topic 842). The FASB issued this update to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The updated guidance is effective for annual periods beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption of the standard is permitted. We plan to adopt the standard in the first quarter of fiscal year 2019 by electing practical expedients available in the standard. While we are currently evaluating the impact of the adoption of this guidance on our consolidated financial statements, we expect the adoption will have a material increase in the assets and liabilities of our consolidated balance sheet.

In March 2016, the FASB issued ASU No. 2016-09, "Improvements to Employee Share-Based Payment Accounting" (Topic 718). This ASU affects entities that issue share-based payment awards to their employees. The ASU is designed to simplify several aspects of accounting for share-based payment award transactions, which include the income tax consequences, classification of awards as either equity or liabilities, classification on the statements of cash flows and forfeiture rate calculations. This ASU is effective for fiscal years beginning after December 15, 2016 and interim periods within those years. We plan to adopt the standard in the first quarter of fiscal year 2017, and the adoption will have a material impact on our consolidated financial statements.

In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments - Credit Losses” (Topic 326). The FASB issued this update to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The amendments in this update replace the existing guidance of incurred loss impairment methodology with an approach that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The updated guidance is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption of the update is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. We are evaluating the impact of the adoption of this update on our consolidated financial statements and related disclosures.

In August 2016, the FASB issued ASU 2016-15, "Classification of Certain Cash Receipts and Cash Payments" (Topic 230). This FASB clarifies the presentation and classification of certain cash receipts and cash payments in the statements of cash flows. This ASU is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. Early adoption is permitted. We are currently evaluating the impact of this guidance on our consolidated financial statements.

In October, 2016, the FASB issued ASU 2016-16, "Intra-Entity Transfers of Assets Other Than Inventory," (Topic 740) which requires entities to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. Prior to the issuance of this ASU, existing guidance prohibited the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset had been sold to an outside party. This ASU is effective for fiscal years beginning after December 15, 2017 and interim periods within those years. Early adoption is permitted. We plan to early adopt the standard in the first quarter of 2017 by applying the modified retrospective approach with a cumulative catch-up adjustment to opening retained earnings at the beginning of the first quarter of 2017. The adoption will impact our consolidated balance sheet but we do not expect the impact to be material.

In November 2016, the FASB issued ASU 2016-18, "Statement of Cash Flows - Restricted Cash," which provides guidance to address the classification and presentation of changes in restricted cash in the statements of cash flows. This standard is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period, but any adjustments must be reflected as of the beginning of the fiscal year that includes that interim period. The new standard must be adopted retrospectively. We are currently in the process of evaluating the impact of this new pronouncement on our consolidated statement of cash flows.

Marketable Securities and Fair Value Measurements

12 Months Ended

Dec. 31, 2016

Investments, All Other Investments [Abstract]

Marketable Securities and Fair Value Measurements

As of December 31, 2016 and 2015, the estimated fair value of our short-term and long-term marketable securities, classified as available for sale, are as follows (in thousands):

Short-term



December 31, 2016	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	42,397	$	—	$	(6	)	$	42,391
Corporate bonds	122,788		22		(121		)	122,689
Municipal securities	5,852		—		(5		)	5,847
U.S. government agency bonds	28,903		9		(4		)	28,908
U.S. government treasury bonds	45,146		7		(7		)	45,146
Certificates of deposit	6,000		—		—			6,000
Total Marketable Securities, Short-Term	$	251,086	$	38	$	(143	)	$	250,981

Long-term



December 31, 2016	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	6,805	$	—	$	(16	)	$	6,789
Corporate bonds	40,889		8		(85		)	40,812
U.S. government treasury bonds	12,016		5		(16		)	12,005
Asset-backed securities	177		—		—			177
Total Marketable Securities, Long-Term	$	59,887	$	13	$	(117	)	$	59,783

Short-term



December 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	38,537	$	—	$	—		$	38,537
Corporate bonds	179,765		6		(251		)	179,520
U.S. dollar dominated foreign corporate bonds	510		—		(2		)	508
Municipal securities	14,209		7		(2		)	14,214
U.S. government agency bonds	75,172		—		(53		)	75,119
U.S. government treasury bonds	51,763		1		(81		)	51,683
Total Marketable Securities, Short-Term	$	359,956	$	14	$	(389	)	$	359,581

Long-term



December 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	43,853	$	—	$	(178	)	$	43,675
Corporate bonds	64,012		9		(218		)	63,803
U.S. government treasury bonds	37,673		—		(107		)	37,566
Municipal securities	3,993		—		(2		)	3,991
Asset-backed securities	2,338		—		(3		)	2,335
Total Marketable Securities, Long-Term	$	151,869	$	9	$	(508	)	$	151,370

Cash and cash equivalents are not included in the table above as the gross unrealized gains and losses are not material. We have no short-term or long-term investments that have been in a continuous material unrealized loss position for greater than twelve months as of December 31, 2016 and 2015. Amounts reclassified to earnings from accumulated other comprehensive income (loss), net related to unrealized gains or losses were not material in 2016 and 2015. For the year ended December 31, 2016 and 2015, realized gains or losses were not material.

Our fixed-income securities investment portfolio consists of corporate bonds, U.S. dollar denominated foreign corporate bonds, commercial paper, municipal securities, U.S. government agency bonds, U.S. government treasury bonds, certificates of deposit and asset-backed securities that have a maximum effective maturity of 27 months. 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 7 months and 9 months as of December 31, 2016 and 2015, respectively.

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, 2016 and 2015 (in thousands):



	December 31,
	2016		2015
One year or less	$	250,981	$	359,581
Due in greater than one year	59,783		151,370
Total available for short-term and long-term marketable securities	$	310,764	$	510,951

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 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 U.S. government treasury bonds. We did not hold any Level 1 liabilities as of December 31, 2016 and 2015.

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, municipal securities, certificates of deposit, U.S. government agency bonds, asset-backed securities and our Israeli funds that are mainly invested in insurance policies. We obtain fair values for our Level 2 investments. 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, 2016 and 2015.

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 methodologies or similar valuation techniques, as well as significant management judgment or estimation. Our Level 3 assets consist of long-term notes receivable and are included in other assets on our consolidated balance sheet. In 2016, we entered into a long-term notes receivable for $2.0 million and we recognized $0.05 million in earnings during 2016 as a result of a change in its fair value. As of December 31, 2016, the fair value of long-term notes receivable was approximately $2.05 million. We did not hold any Level 3 liabilities as of December 31, 2016 and 2015.

The following tables summarize our financial assets measured at fair value on a recurring basis as of December 31, 2016 and 2015 (in thousands):



Description	Balance as of December 31, 2016		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Observable Inputs (Level 3)
Cash equivalents:
Money market funds	$	87,179	$	87,179	$	—	$	—
Commercial paper	2,499		—		2,499		—
Corporate bonds	750		—		750		—
Short-term investments:
Commercial paper	42,391		—		42,391		—
Corporate bonds	122,689		—		122,689		—
Municipal securities	5,847		—		5,847		—
U.S. government agency bonds	28,908		—		28,908		—
U.S. government treasury bonds	45,146		45,146		—		—
Certificates of deposit	6,000		—		6,000		—
Long-term investments:
U.S. government agency bonds	6,789		—		6,789		—
Corporate bonds	40,812		—		40,812		—
U.S. government treasury bonds	12,005		12,005		—		—
Asset-backed securities	177		—		177		—
Prepaid expenses and other current assets:
Israeli funds	2,956		—		2,956		—
Other assets:
Long-term notes receivable	2,047		—		—		2,047
	$	406,195	$	144,330	$	259,818	$	2,047



Description	Balance as of December 31, 2015		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	70,148	$	70,148	$	—
Commercial paper	36,887		—		36,887
U.S. government agency bonds	3,599		—		3,599
Corporate bonds	625		—		625
Short-term investments:
Commercial paper	38,537		—		38,537
Corporate bonds	179,520		—		179,520
U.S. dollar denominated foreign corporate bonds	508		—		508
Municipal securities	14,214		—		14,214
U.S. government agency bonds	75,119		—		75,119
U.S. government treasury bonds	51,683		51,683		—
Long-term investments:
U.S. government agency bonds	43,675		—		43,675
Corporate bonds	63,803		—		63,803
U.S. government treasury bonds	37,566		37,566		—
Municipal securities	3,991		—		3,991
Asset-backed securities	2,335		—		2,335
Prepaid expenses and other assets:
Israeli funds	2,436		—		2,436
	$	624,646	$	159,397	$	465,249

Derivative Financial Instruments

We have in the past and may in the future enter into foreign currency forward contracts to minimize the short-term impact of foreign currency exchange rate fluctuations associated with certain assets and liabilities. The net loss on these forward contracts was not material for the year ended December 31, 2016 and 2015. The net gain or loss from the settlement of these foreign currency forward contracts is recorded in interest and other income (expenses), net in the Consolidated Statements of Operations. We had no material foreign exchange forward contracts outstanding as of December 31, 2016 and 2015. Certain investments in private companies contain embedded derivatives, which do not require bifurcation as we have elected to measure these investments at fair value.

Balance Sheet Components

12 Months Ended

Dec. 31, 2016

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Components

Inventories

Inventories consist of the following (in thousands):



	December 31,
	2016		2015
Raw materials	$	9,793	$	9,950
Work in process	10,773		7,067
Finished goods	6,565		2,448
Total Inventories	$	27,131	$	19,465

Property, Plant and Equipment

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



		December 31,
	Generally Used Estimated Useful Life	2016			2015
Clinical and manufacturing equipment	Up to 10 years	$	153,938		$	128,044
Computer hardware	3 years	27,978			25,843
Computer software	3 years	59,997			21,451
Furniture and fixtures	5 years	10,306			8,855
Leasehold improvements	Lease term ⁽¹⁾	22,370			20,172
Building	20 years	7,272			4,227
Land	—	3,072			3,072
CIP	—	25,948			42,846
Total		310,881			254,510
Less: Accumulated depreciation and amortization and impairment charges		(135,714		)	(118,037		)
Total Property, plant and equipment, net		$	175,167		$	136,473

⁽¹⁾ Shorter of remaining lease term or estimated useful lives of assets.

Depreciation and amortization was $24.0 million, $18.0 million and $17.9 million, for the year ended December 31, 2016, 2015 and 2014, respectively.

Accrued Liabilities

Accrued liabilities consist of the following (in thousands):



	December 31,
	2016		2015
Accrued payroll and benefits	$	79,214	$	55,430
Accrued sales and marketing expenses	11,970		7,071
Accrued sales rebate	10,342		8,486
Accrued sales tax and value added tax	5,032		4,801
Accrued income taxes	4,210		2,646
Accrued warranty	3,841		2,638
Accrued professional fees	3,604		2,775
Other accrued liabilities	16,119		23,918
Total Accrued Liabilities	$	134,332	$	107,765

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

We warrant our Invisalign products against material defects until the aligner case is complete. We warrant SDC products against material defects for one year. 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.

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, 2016 and 2015 consists of the following activity (in thousands):



Warranty accrual, December 31, 2014	$	3,148
Charged to cost of revenues	1,796
Actual warranty expenditures	(2,306		)
Warranty accrual, December 31, 2015	2,638
Charged to cost of revenues	4,894
Actual warranty expenditures	(3,691		)
Warranty accrual, December 31, 2016	$	3,841

Equity Method Investments	12 Months Ended
Equity Method Investments	Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments On July 25, 2016, we acquired a 17% equity interest, on a fully diluted basis, in SmileDirectClub, LLC (“SDC”) for $46.7 million, and account for this as an equity method investment. The investment is reported on our consolidated balance sheet as a single amount under equity method investments, and we record our proportional share of SDC's earnings or losses within equity in losses of investee in our consolidated statement of operations. As of December 31, 2016, the balance of our equity method investments was $45.1 million. Concurrently with the investment on July 25, 2016, we also entered into a supply agreement with SDC to manufacture clear aligners for SDC's doctor-led, at-home program for simple teeth straightening. The term of the supply agreement expires on December 31, 2019. We commenced supplying aligners to SDC in October 2016. The sale of aligners to SDC and the income from under the supply agreement are reported in our Clear Aligner business segment after eliminating outstanding intercompany transactions.

Goodwill and Intangible Assets

12 Months Ended

Dec. 31, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

Goodwill

The change in the carrying value of goodwill for the year ended December 31, 2016, all attributable to our Clear Aligner reporting unit, is as follows (in thousands):



	Total
Balance as of December 31, 2014	$	61,369
Adjustments ⁽¹⁾	(295		)
Balance as of December 31, 2015	61,074
Adjustments ⁽¹⁾	(30		)
Balance as of December 31, 2016	$	61,044

⁽¹⁾The adjustments to goodwill were a result of foreign currency translation.

Impairment of Goodwill

Annual Impairment Test

The remaining goodwill is entirely attributable to our Clear Aligner reporting unit. During the fourth quarter of fiscal 2016, we performed the annual goodwill impairment testing and found no impairment as the fair value of our Clear Aligner reporting unit was significantly in excess of the carrying value.

Intangible Long-Lived 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 intraoral scanning business.

There were no triggering events in 2016 that would cause impairments of our long-lived assets.

Acquired intangible long-lived assets are being amortized as follows (in thousands):



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2016		Accumulated Amortization			Accumulated Impairment Loss			Net Carrying Value as of December 31, 2016
Trademarks	15	$	7,100	$	(1,631	)	$	(4,179	)	$	1,290
Existing technology	13	12,600		(4,141		)	(4,328		)	4,131
Customer relationships	11	33,500		(12,819		)	(10,751		)	9,930
Patents	8	6,316		(713		)	—			5,603
Total Intangible Assets		$	59,516	$	(19,304	)	$	(19,258	)	$	20,954



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2015		Accumulated Amortization			Accumulated Impairment Loss			Net Carrying Value as of December 31, 2015
Trademarks	15	$	7,100	$	(1,492	)	$	(4,179	)	$	1,429
Existing technology	13	12,600		(3,577		)	(4,328		)	4,695
Customer relationships	11	33,500		(10,957		)	(10,751		)	11,792
Patents	8	285		(113		)	—			172
Total Intangible Assets		$	53,485	$	(16,139	)	$	(19,258	)	$	18,088

The total estimated annual future amortization expense for these acquired intangible assets as of December 31, 2016 is as follows (in thousands):



Fiscal Year
2017	$	3,355
2018	3,353
2019	3,346
2020	3,336
2021	3,334
Thereafter	4,230
Total	$	20,954

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.

Commitments and Contingencies Disclosure [Abstract]

Legal Proceedings	12 Months Ended
Legal Proceedings	Dec. 31, 2016
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 former 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 (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 attorneys’ fees. On December 9, 2013, the court granted defendants’ 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 states the same claims as the amended complaint. On August 22, 2014, the court granted our motion to dismiss without leave to amend. On September 22, 2014, Plaintiff filed a notice of appeal to the Ninth Circuit Court of Appeals. Briefing for the appeal was completed in May 2015 and the Ninth Circuit held oral arguments in October 2016. Align intends to vigorously defend itself against these allegations. Align is currently unable to predict the outcome of this amended complaint and therefore cannot determine the likelihood of loss nor estimate a range of possible loss, if any. 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 attorneys’ 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. On October 14, 2014, an Order was entered staying this derivative lawsuit until a ruling by the Ninth Circuit in the Securities Action discussed above. 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, if any. 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, 2016
Debt Disclosure [Abstract]
Credit Facilities	Credit Facility The credit facility provides for a $50.0 million revolving line of credit, with a $10.0 million letter of credit sublimit. The credit facility requires us to comply with specific financial conditions and performance requirements. On December 13, 2016, we amended the credit facility to remove the requirement to maintain a minimum unrestricted cash balance of $50.0 million. On February 10, 2017, we amended the credit facility and extended the maturity date to March 22, 2018. 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, 2016, we had no outstanding borrowings under this credit facility and were in compliance with the conditions and performance requirements.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2016

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 2024 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 $9.9 million, $8.2 million and $7.6 million, for the year ended December 31, 2016, 2015 and 2014, respectively.

Minimum future lease payments for non-cancelable leases as of December 31, 2016, are as follows (in thousands):



Fiscal Year	Operating Leases
2017	$	12,880
2018	10,338
2019	8,466
2020	6,849
2021	6,247
Thereafter	9,141
Total minimum lease payments	$	53,921

Other Commitments

On July 25, 2016, we entered into a Loan and Security Agreement (the "Loan Agreement") with SmileDirectClub, LLC ("SDC") where we agreed to provide a loan of up to $15.0 million in one or more advances to SDC (the "Loan Facility"). Available advances under the Loan Facility are subject to a borrowing base of 80% of SDC's eligible accounts receivable, determined in accordance with the terms of the Loan Agreement, and the satisfaction of other customary conditions. The advances bear interest, paid quarterly, at the rate of 7% per annum. Advances that are repaid or prepaid may be reborrowed. All outstanding principal and accrued and unpaid interest on the advances are due and payable on July 25, 2021. SDC's obligations in respect of the Loan Agreement are collateralized by a security interest in substantially all of SDC's assets. As of December 31, 2016, no advances on the Loan Facility were issued or outstanding (Refer to Note 4 "Equity Method Investments" of the Notes of Consolidated Financial Statements for more information on our investments in SDC).

We have entered into certain investments with a privately held company where we have committed to purchase up to $5.0 million in convertible promissory notes. The first convertible promissory note for $2.0 million was issued in July 2016 and is outstanding as of December 31, 2016. The remaining $3.0 million is conditioned upon achievement of various business milestones. The notes all mature on December 30, 2018 and accrue interest annually at 2.5%.

On December 19, 2016, we entered into a Purchase and Sale Agreement (the "Purchase Agreement") with LBA RIV-COMPANY XXX, LLC ("Seller") to purchase the real property located in San Jose, California (the "Property") for purchase price of $44.1 million. The Property is comprised of land, building and other fixtures as set forth in the Purchase Agreement. As of December 31, 2016, $1.0 million was deposited into escrow and recorded in other current assets in our Consolidated Balance Sheet. We had a right to inspect the Property until January 6, 2017 and if we decided to terminate the Purchase Agreement during the period, the deposit would have been refunded to us. On January 26, 2017, we paid the purchase price of $44.1 million and closed the Purchase Agreement.

Off-Balance Sheet Arrangements

As of December 31, 2016, 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 our executive 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, 2016, we did not have any material indemnification claims that were probable or reasonably possible.

Stockholders' Equity

12 Months Ended

Dec. 31, 2016

Stockholders' Equity Note [Abstract]

Stockholders' Equity

Stockholders’ Equity

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.

As of December 31, 2016, the 2005 Incentive Plan (as amended) has a total reserve of 27,783,379 shares for issuance of which 8,023,709 shares are available for issuance. In 2016, we added 4,500,000 shares to our pool and no shares were added to the plan in 2015. 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, 2016, 2015 and 2014 is as follows (in thousands):



	For the Year Ended December 31,
	2016		2015		2014
Cost of net revenues	$	3,966	$	3,938	$	3,616
Selling, general and administrative	42,612		40,813		29,625
Research and development	7,570		8,192		6,582
Total stock-based compensation	$	54,148	$	52,943	$	39,823

Stock Options

We have not granted options since 2011 and all outstanding options were fully vested in 2015. Activity for the year ended December 31, 2016, 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, 2015	496		15.14
Granted	—		—
Exercised	(274	)	15.33
Cancelled or expired	—		—
Outstanding as of December 31, 2016	222		$	14.90	1.12	$	18,058
Vested and expected to vest at December 31, 2016	222		$	14.90	1.12	$	18,058
Exercisable at December 31, 2016	222		$	14.90	1.12	$	18,058

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 2016 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 the last trading day of 2016. This amount will fluctuate based on the fair market value of our stock. The total intrinsic value of stock options exercised for the year ended December 31, 2016, 2015 and 2014 was $18.2 million, $7.4 million and $24.5 million, respectively. The total fair value of the options vested during the year ended December 31, 2016, 2015 and 2014 was not material.

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, 2016, is as follows (in thousands, except years and per share amounts):



	Shares Underlying RSUs		Weighted Average Grant Date Fair Value		Weighted Remaining Vesting Period (in years)	Aggregate Intrinsic Value
Nonvested as of December 31, 2015	2,079		$	49.45
Granted	714		67.82
Vested and released	(859	)	45.45
Forfeited	(145	)	53.36
Nonvested as of December 31, 2016	1,789		$	58.39	1.12	$	171,934

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 2016 by the number of nonvested RSUs) that would have been received by the unit holders had all RSUs been vested and released as of the last trading day of 2016. This amount will fluctuate based on the fair market value of our stock. During 2016, of the 859,410 shares vested and released, 300,031 vested shares were withheld for employee minimum statutory tax obligations, resulting in a net issuance of 559,379 shares.

The total intrinsic value of RSUs vested and released during 2016, 2015 and 2014 was $59.8 million, $45.9 million and $38.9 million, respectively. The total fair value RSUs vested during the year ended December 31, 2016, 2015 and 2014 was $39.1 million, $30.0 million and $22.0 million, respectively. The weighted average grant date fair value of RSUs granted during 2016, 2015 and 2014 was $67.82, $57.78 and $53.72, respectively. As of December 31, 2016, there was $63.3 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 2.0 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, 2016:



	Number of Shares Underlying MSUs (in thousands)		Weighted Average Grant Date Fair Value	Weighted Average Remaining Vesting Period (in years )	Aggregate Intrinsic Value (in thousands)
Nonvested as of December 31, 2015	611		51.41
Granted	218		55.77
Vested and released	(270	)	36.73
Forfeited	(39	)	56.41
Nonvested as of December 31, 2016	520		60.49	1.1	$	50,021

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 2016 by the number of non-vested MSUs) that would have been received by the unit holders had all MSUs been vested and released as of the last trading day of 2016. This amount will fluctuate based on the fair market value of our stock. During 2016, of the 270,347 shares vested and released 136,758 shares were withheld for tax payments, resulting in a net issuance of 133,589 shares.

The total intrinsic value of MSUs vested and released during 2016, 2015 and 2014 was $17.4 million, $9.2 million and $2.9 million. The total fair value MSUs vested during the year ended December 31, 2016, 2015 and 2014 was $9.9 million, $4.9 million and $1.2 million, respectively. As of December 31, 2016, we expect to recognize $11.1 million of total unamortized compensation cost, net of estimated forfeitures, related to MSUs over a weighted average period of 1.1 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,
	2016			2015			2014
Expected term (in years)	3			3			3
Expected volatility	34.0		%	36.9		%	46.0		%
Risk-free interest rate	0.9		%	1.0		%	0.7		%
Expected dividends	—			—			—
Weighted average fair value per share at grant date	$	68.88		$	61.73		$	50.46

Total payments to tax authorities for payroll taxes related to RSUs, including MSUs, that vested during the period were $29.9 million, $20.7 million and $7.6 million during the year ended December 31, 2016, 2015 and 2014, respectively, reflected as a financing activity in the Consolidated Statement of Cash Flows.

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 of Directors 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, 2016, 2015 and 2014, we issued 196,882, 230,078 and 247,343 shares, respectively, at average prices of $48.65, $36.66 and $29.24, respectively. As of December 31, 2016, 936,867 shares remain available for future issuance.

The fair value of the option component of the 2010 Purchase Plan shares was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:



	Year Ended December 31,
	2016			2015			2014
Expected term (in years)	1.2			1.2			1.2
Expected volatility	30.5		%	31.1		%	38.8		%
Risk-free interest rate	0.7		%	0.3		%	0.2		%
Expected dividends	—			—			—
Weighted average fair value at grant date	$	22.23		$	16.19		$	17.15

We recognized stock-based compensation expense of $2.7 million, $4.1 million and $2.6 million related to our employee stock purchase plans for the year ended December 31, 2016, 2015 and 2014, respectively. As of December 31, 2016, there was $0.7 million of total unamortized compensation costs related to employee stock purchases which we expect to be recognized over a weighted average period of 0.3 years.

Supplemental Cash Flow Information [Abstract]

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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Reference 15: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Common Stock Repurchase Program	12 Months Ended
Common Stock Repurchase Program	Dec. 31, 2016
Notes To Financial Statements [Abstract]
Share Repurchase Program Disclosure	Common Stock Repurchase Program April 2014 Repurchase Program On April 23, 2014, we announced that our Board of Directors had authorized a stock repurchase program ("April 2014 Repurchase Program") pursuant to which we may purchase up to $300.0 million of our common stock over a three year period. In 2014, we entered into an accelerated share repurchase agreement ("2014 ASR") to repurchase $70.0 million of our common stock. The 2014 ASR was completed in July 2014. We received a total of approximately 1.4 million shares for an average purchase price per share of $51.46. During 2014, we repurchased on the open market approximately 0.6 million shares of our common stock at an average price of $50.93 per share, including commissions, for an aggregate purchase price of approximately $28.2 million. In 2015, we entered into an accelerated share purchase agreement ("2015 ASR") to repurchase $70.0 million of our common stock. The 2015 ASR was completed in July 2015. We received a total of approximately 1.2 million shares for an average share price of $60.52. During 2015, we repurchased on the open market approximately 0.5 million shares of our common stock at an average price of $58.89 per share, including commissions, for an aggregate purchase price of approximately $31.8 million. In 2016, we entered into an accelerated share repurchase agreement ("2016 ASR") to repurchase $50.0 million of our common stock. The 2016 ASR was completed in September 2016. We received a total of approximately 0.6 million shares for an average share price of $81.89. During 2016, we repurchased on the open market approximately 0.5 million shares of our common stock at an average price of $92.58 per share, including commissions, for an aggregate purchase price of approximately $46.2 million. All shares repurchased in 2016, 2015 and 2014 were retired. As of December 31, 2016, we have $3.8 million remaining under the April 2014 Repurchase Program. April 2016 Repurchase Program On April 28, 2016, we announced that our Board of Directors had authorized an additional plan to repurchase up to $300.0 million of the Company's stock ("April 2016 Repurchase Plan"). Any purchases under this stock repurchase program may be made, from time-to-time, pursuant to open market purchases (including pursuant to Rule 10b5-1 plans), privately-negotiated transactions, accelerated stock repurchases, block trades or derivative contracts or otherwise in accordance with applicable federal securities laws, including Rule 10b-18 of the Securities Exchange Act of 1934. As of December 31, 2016, there have not been any repurchases under this plan.

Employee Benefit Plans	12 Months Ended
Employee Benefit Plans	Dec. 31, 2016
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 $3.4 million, $2.7 million and $2.2 million to the 401(k) plan during the year ended December 31, 2016, 2015 and 2014, 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 current assets. As of December 31, 2016 and 2015, the accrued funds liability was approximately $3.1 million and $2.7 million, respectively.

Income Taxes

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Income Taxes

Net income before provision for income taxes and equity in losses of investee consist of the following (in thousands):



	Year ended December 31,
	2016		2015		2014
Domestic	$	118,871	$	87,803	$	94,784
Foreign	123,695		98,298		95,585
Net income before provision for income taxes and equity in losses of investee	$	242,566	$	186,101	$	190,369

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



	Year Ended December 31,
	2016			2015			2014
Federal
Current	$	40,235		$	28,596		$	1,569
Deferred	24,794			6,679			37,570
	65,029			35,275			39,139
State
Current	2,603			3,271			2,162
Deferred	2,636			(703		)	971
	5,239			2,568			3,133
Foreign
Current	8,964			4,305			1,596
Deferred	(28,032		)	(67		)	669
	(19,068		)	4,238			2,265
Provision for income taxes	$	51,200		$	42,081		$	44,537

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



	Year Ended December 31,
	2016		2015		2014
U.S. federal statutory income tax rate	35.0	%	35.0	%	35.0	%
State income taxes, net of federal tax benefit	2.1		1.5		1.6
Impact of differences in foreign tax rates	(6.3	)	(16.2	)	(16.4	)
Valuation allowance release for Israel	(12.9	)	—		—
Stock-based compensation	1.2		1.6		1.0
Other items not individually material	2.0		0.7		2.2
	21.1	%	22.6	%	23.4	%

As of December 31, 2016, approximately $438.0 million of undistributed earnings from non-U.S. operations held by our foreign subsidiaries are designated as indefinitely reinvested outside the U.S. We maintain sufficient cash reserves in the U.S. and do not intend to repatriate our foreign earnings. As a result, U.S. income taxes and foreign withholding taxes have not been provided on these foreign earnings. 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 credits and foreign withholding taxes. We intend to use the undistributed earnings for local operating expansions and to meet local operating working capital needs. In addition, a significant amount of the cash earned by foreign subsidiaries has been and will continue to be utilized to affect the new international corporate structure described above.

On July 1, 2016, we implemented a new international corporate structure. This changes the structure of our international procurement and sales operations, as well as realigns the ownership and use of intellectual property among our wholly-owned subsidiaries. We continue to anticipate that an increasing percentage of our consolidated pre-tax income will be derived from, and reinvested in our foreign operations. We believe that income taxed in certain foreign jurisdictions at a lower rate relative to the U.S. federal statutory rate will have a beneficial impact on our worldwide effective tax rate over time. Although the license of intellectual property rights between consolidated entities did not result in any gain in the consolidated financial statements, the Company generated taxable income in certain jurisdictions in 2016 resulting in a tax expense of $34.3 million. Additionally, as a result of the restructuring, we reassessed the need for a valuation allowance against our deferred tax assets considering all available evidence. Given the current earnings and anticipated future earnings of our subsidiary in Israel, we concluded that we have sufficient positive evidence to release the valuation allowance against our Israel operating loss carryforwards of $31.4 million, which resulted in an income tax benefit in this period of the same amount.

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 July 2017. We intend to seek a renewal of these income tax incentives before they expire. Under these incentives, all of the income in Costa Rica during these twelve year incentive periods is subject to a reduced tax rate. In order to receive the benefit of these incentives, we must hire specified numbers of employees and maintain certain 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 2016, 2015 and 2014. As a result of these incentives, income taxes were reduced by $19.1 million, $32.7 million and $32.5 million in the year ended December 31, 2016, 2015 and 2014, respectively. The benefit of the tax holiday on diluted net income per share was $0.23 in the year ended December 31, 2016 and $0.40 for both the year ended December 31, 2015 and 2014.

As of December 31, 2016 and 2015, the significant components of our deferred tax assets and liabilities are (in thousands):



	Year Ended December 31,
	2016			2015
Deferred tax assets:
Net operating loss and capital loss carryforwards	$	25,445		$	31,247
Reserves and accruals	22,954			17,455
Stock-based compensation	16,399			16,523
Deferred revenue	13,975			24,432
Net translation losses	1,634			649
Credit carryforwards	679			1,932
	81,086			92,238
Deferred tax liabilities:
Depreciation and amortization	12,034			8,555
Prepaid expenses	969			601
	13,003			9,156
Net deferred tax assets before valuation allowance	68,083			83,082
Valuation allowance	(256		)	(31,685		)
Net deferred tax assets	$	67,827		$	51,397

As of December 31, 2016, the valuation allowance decreased by $31.4 million in comparison to the balance at December 31, 2015. This decrease was due to the release of the valuation allowance against our Israel net deferred tax assets during the year. We determined that these deferred tax assets are more likely than not to be realized based upon our assessment of the available positive and negative evidence. Positive evidence, including expected profitability based upon the implementation of our international corporate restructuring outweighed available negative evidence, which included losses in recent years. The total valuation allowance as of December 31, 2016 was not material.

As of December 31, 2016, we have fully utilized California net operating loss carryforwards. As of December 31, 2016, we have California research credit carryforwards of approximately $3.7 million which can be carried forward indefinitely. In addition, we have foreign net operating loss carryforwards of approximately $104.3 million, which, if not utilized will expire beginning in 2025.

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

The changes in the balance of gross unrecognized tax benefits, which exclude interest and penalties, for the year ended December 31, 2016, 2015 and 2014, are as follows (in thousands):



Unrecognized tax benefit as of December 31, 2013	$	26,668
Tax positions related to current year:
Additions for uncertain tax positions	6,659
Tax positions related to prior year:
Reductions for uncertain tax positions	(260		)
Unrecognized tax benefit as of December 31, 2014	33,067
Tax positions related to current year:
Additions for uncertain tax positions	6,346
Unrecognized tax benefit as of December 31, 2015	39,413
Tax positions related to current year:
Additions for uncertain tax positions	6,971
Unrecognized tax benefit as of December 31, 2016	$	46,384

We account for uncertain tax positions 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 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 2016, the amount of gross unrecognized tax benefits increased by $7.0 million in comparison to fiscal year 2015. The total amount of unrecognized tax benefits, excluding interest and penalties, was $46.4 million and $39.4 million as of December 31, 2016 and 2015, respectively, 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 taxes. For the year ended December 31, 2016 and 2015, interest and penalties included in tax expense was $1.4 million and $0.7 million, respectively. Our total interest and penalties accrued as of December 31, 2016 and 2015 was $2.1 million and $0.7 million, respectively. We do not expect any significant changes to the amount of unrecognized tax benefit within the next twelve months.

We file U.S. federal, U.S. state, and non-U.S. income tax returns. Our major tax jurisdictions are U.S. federal and the State of California. For U.S. federal and state tax returns, we are no longer subject to tax examinations for years before 2000. With few exceptions, we are no longer subject to examination by foreign tax authorities for years before 2007. Our subsidiary in Israel is under audit by the local tax authorities for calendar years 2006 through 2013.

Net Income per Share

12 Months Ended

Dec. 31, 2016

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 any dilutive effect of potential common stock. Potential common stock, computed using the treasury stock method, includes RSU, MSU, stock options and our ESPP.

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,
	2016		2015		2014
Numerator:
Net income	$	189,682	$	144,020	$	145,832
Denominator:
Weighted-average common shares outstanding, basic	79,856		79,998		80,754
Dilutive effect of potential common stock	1,628		1,523		1,529
Total shares, diluted	81,484		81,521		82,283
Net income per share, basic	$	2.38	$	1.80	$	1.81
Net income per share, diluted	$	2.33	$	1.77	$	1.77

For the year ended December 31, 2016, 2015 and 2014, the anti-dilutive effect on net income per share from RSUs, MSUs and ESPP was not material.

Supplemental Cash Flow Information

12 Months Ended

Dec. 31, 2016

Supplemental Cash Flow Information

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



	Year Ended December 31,
	2016		2015		2014
Taxes paid	$	47,289	$	40,621	$	5,666
Non-cash investing activities:
Fixed assets acquired with accounts payable or accrued liabilities	$	4,434	$	14,636	$	4,899

Segments and Geographical Information

12 Months Ended

Dec. 31, 2016

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. In the fourth quarter of 2016, management decided to change the way it internally assesses the performance of our reportable segments by including income from operations measure in the performance metrics. Income from operations for each segment includes all geographic revenues, related cost of net revenues and operating expenses directly attributable to the segment. Certain operating expenses are attributable to operating segments and each allocation is measured differently based on the specific facts and circumstances of the costs being allocated. Costs not specifically allocated to segment income from operations include various corporate expenses such as stock-based compensation and costs related to IT, facilities, human resources and accounting and finance, legal and regulatory, and other separately managed general and administrative costs outside the operating segments. We have included the new performance measure in the prior periods presentation to conform to the current year’s presentation.

We have grouped our operations into two reportable segments which are also our reporting units: Clear Aligner segment and Scanner 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. Clear Aligner segment also include the sale of aligners to SDC under our supply agreement which commenced in the fourth quarter of 2016. SDC revenue is recorded after eliminating outstanding intercompany transactions.


•	Our Scanner and Services ("Scanner") segment consists of intraoral scanning systems and additional services available with the intraoral scanners that provide digital alternatives to the traditional cast models. This segment includes our iTero scanner and OrthoCAD services.

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	2016			2015			2014
Clear Aligner	$	958,327		$	800,186		$	712,549
Scanner	121,547			45,300			49,104
Total net revenues	$	1,079,874		$	845,486		$	761,653
Gross Profit
Clear Aligner	$	747,494		$	628,187		$	562,889
Scanner	67,800			11,923			15,554
Total gross profit	$	815,294		$	640,110		$	578,443
Income from Operations
Clear Aligner	$	411,817		$	371,113		$	341,055
Scanner	37,498			(12,337		)	(8,483		)
Unallocated corporate expenses	(200,394		)	(170,142		)	(138,996		)
Total income from operations	$	248,921		$	188,634		$	193,576
Depreciation and Amortization
Clear Aligner	$	13,742		$	9,842		$	8,706
Scanner	3,871			3,839			4,498
Unallocated corporate expenses	6,389			4,323			4,652
Total depreciation and amortization	$	24,002		$	18,004		$	17,856

The following table reconciles total segment income from operations in the table above to net income before provision for income taxes and equity losses of investee:



	For the Year Ended December 31,
	2016			2015			2014
Total segment income from operations	$	449,315		$	358,776		$	332,572
Unallocated corporate expenses	(200,394		)	(170,142		)	(138,996		)
Total income from operations	248,921			188,634			193,576
Interest and other income (expense), net	(6,355		)	(2,533		)	(3,207		)
Net income before provision for income taxes and equity losses of investee	$	242,566		$	186,101		$	190,369

Geographical Information

Net revenues are presented below by geographic area (in thousands):



	For the Year Ended December 31,
	2016		2015		2014
Net revenues⁽¹⁾:
United States ⁽²⁾	$	692,254	$	585,874	$	532,569
The Netherlands ⁽²⁾	291,053		167,128		156,817
Other International	96,567		92,484		72,267
Total net revenues	$	1,079,874	$	845,486	$	761,653


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

⁽²⁾ During 2016, we implemented a new international corporate structure. This changed the structure of our international procurement and sales operations.

Tangible long-lived assets are presented below by geographic area (in thousands):



	As of December 31,
	2016		2015
Long-lived assets ⁽¹⁾:
The Netherlands ⁽²⁾	$	111,515	$	486
United States ⁽²⁾	43,278		112,632
Mexico	17,918		15,422
Other International	2,456		7,933
Total long-lived assets	$	175,167	$	136,473

⁽¹⁾ Long-lived assets are attributed to countries based on entity that owns the assets.

⁽²⁾ As a result of the new international corporate structure changes, approximately $92.0 million in long-lived assets were transferred from the U.S. to our Netherlands entity in 2016.

Valuation and Qualifying Accounts [Abstract]

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.

+ References

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+ Details

Schedule II: Valuation and Qualifying Accounts and Reserves

12 Months Ended

Dec. 31, 2016

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			Balance at End of Period
	(in thousands)
Allowance for doubtful accounts and returns:
Year ended December 31, 2014	$	1,733	$	6,563		$	(6,733	)	$	1,563
Year ended December 31, 2015	$	1,563	$	8,944		$	(8,035	)	$	2,472
Year ended December 31, 2016	$	2,472	$	8,585		$	(6,747	)	$	4,310
Valuation allowance for deferred tax assets:
Year ended December 31, 2014	$	35,108	$	(1,793	)	$	(817	)	$	32,498
Year ended December 31, 2015	$	32,498	$	(813	)	$	—		$	31,685
Year ended December 31, 2016	$	31,685	$	(31,429	)	$	—		$	256

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Business Description

Basis of presentation and preparation

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.

Reclassification, Policy

Out of Period Adjustment

Use of estimates

Use of Estimates

Fair value of financial instruments

Fair Value of Financial Instruments

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

Cash and Cash Equivalents

Restricted cash

Restricted Cash

Marketable Securities

Consolidation of Variable Interest Entities

Variable Interest Entities

Investments in Privately Held Companies

Derivative Financial Instruments

Foreign currency

Foreign Currency

Certain risks and uncertainties

Certain Risks and Uncertainties

Inventories

Property, plant and equipment

Property, Plant and Equipment

Goodwill and finite-lived purchased intangible assets

Goodwill and Finite-Lived Acquired Intangible Assets

Impairment of goodwill and long-lived assets

Impairment of Goodwill and Long-Lived Assets

Goodwill

Finite-Lived Intangible Assets and Long-Lived Assets

There were no triggering events in 2016 that would cause impairments of our goodwill or long-lived assets.

Development costs for internal use software

Development Costs for Internal Use Software

Product Warranty

Clear Aligner

Scanners and Services

Allowance for Doubtful Accounts

Allowance for Doubtful Accounts and Returns

Revenue recognition

Revenue Recognition


•	VSOE - In most instances, this applies to products and services that are sold separately in stand-alone arrangements. We determine VSOE based on 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.

•

Clear Aligner

Scanners and 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

Research and Development

Advertising costs

Advertising Costs

The cost of advertising and media is expensed as incurred. For the year ended December 31, 2016, 2015 and 2014, advertising costs totaled $36.0 million, $23.4 million and $26.9 million, respectively.

Common Stock Repurchase

Operating Leases

Income taxes

Income Taxes

Stock-based compensation

Stock-Based Compensation

Comprehensive income

Comprehensive Income

Recent Accounting Pronouncements

Earnings Per Share

Marketable Securities and Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

Investments, All Other Investments [Abstract]

Short-Term And Long-Term Marketable Securities

As of December 31, 2016 and 2015, the estimated fair value of our short-term and long-term marketable securities, classified as available for sale, are as follows (in thousands):

Short-term



December 31, 2016	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	42,397	$	—	$	(6	)	$	42,391
Corporate bonds	122,788		22		(121		)	122,689
Municipal securities	5,852		—		(5		)	5,847
U.S. government agency bonds	28,903		9		(4		)	28,908
U.S. government treasury bonds	45,146		7		(7		)	45,146
Certificates of deposit	6,000		—		—			6,000
Total Marketable Securities, Short-Term	$	251,086	$	38	$	(143	)	$	250,981

Long-term



December 31, 2016	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	6,805	$	—	$	(16	)	$	6,789
Corporate bonds	40,889		8		(85		)	40,812
U.S. government treasury bonds	12,016		5		(16		)	12,005
Asset-backed securities	177		—		—			177
Total Marketable Securities, Long-Term	$	59,887	$	13	$	(117	)	$	59,783

Short-term



December 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	38,537	$	—	$	—		$	38,537
Corporate bonds	179,765		6		(251		)	179,520
U.S. dollar dominated foreign corporate bonds	510		—		(2		)	508
Municipal securities	14,209		7		(2		)	14,214
U.S. government agency bonds	75,172		—		(53		)	75,119
U.S. government treasury bonds	51,763		1		(81		)	51,683
Total Marketable Securities, Short-Term	$	359,956	$	14	$	(389	)	$	359,581

Long-term



December 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	43,853	$	—	$	(178	)	$	43,675
Corporate bonds	64,012		9		(218		)	63,803
U.S. government treasury bonds	37,673		—		(107		)	37,566
Municipal securities	3,993		—		(2		)	3,991
Asset-backed securities	2,338		—		(3		)	2,335
Total Marketable Securities, Long-Term	$	151,869	$	9	$	(508	)	$	151,370

Marketable Securities



	December 31,
	2016		2015
One year or less	$	250,981	$	359,581
Due in greater than one year	59,783		151,370
Total available for short-term and long-term marketable securities	$	310,764	$	510,951

Financial Assets Measured At Fair Value On A Recurring Basis

The following tables summarize our financial assets measured at fair value on a recurring basis as of December 31, 2016 and 2015 (in thousands):



Description	Balance as of December 31, 2016		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Observable Inputs (Level 3)
Cash equivalents:
Money market funds	$	87,179	$	87,179	$	—	$	—
Commercial paper	2,499		—		2,499		—
Corporate bonds	750		—		750		—
Short-term investments:
Commercial paper	42,391		—		42,391		—
Corporate bonds	122,689		—		122,689		—
Municipal securities	5,847		—		5,847		—
U.S. government agency bonds	28,908		—		28,908		—
U.S. government treasury bonds	45,146		45,146		—		—
Certificates of deposit	6,000		—		6,000		—
Long-term investments:
U.S. government agency bonds	6,789		—		6,789		—
Corporate bonds	40,812		—		40,812		—
U.S. government treasury bonds	12,005		12,005		—		—
Asset-backed securities	177		—		177		—
Prepaid expenses and other current assets:
Israeli funds	2,956		—		2,956		—
Other assets:
Long-term notes receivable	2,047		—		—		2,047
	$	406,195	$	144,330	$	259,818	$	2,047



Description	Balance as of December 31, 2015		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	70,148	$	70,148	$	—
Commercial paper	36,887		—		36,887
U.S. government agency bonds	3,599		—		3,599
Corporate bonds	625		—		625
Short-term investments:
Commercial paper	38,537		—		38,537
Corporate bonds	179,520		—		179,520
U.S. dollar denominated foreign corporate bonds	508		—		508
Municipal securities	14,214		—		14,214
U.S. government agency bonds	75,119		—		75,119
U.S. government treasury bonds	51,683		51,683		—
Long-term investments:
U.S. government agency bonds	43,675		—		43,675
Corporate bonds	63,803		—		63,803
U.S. government treasury bonds	37,566		37,566		—
Municipal securities	3,991		—		3,991
Asset-backed securities	2,335		—		2,335
Prepaid expenses and other assets:
Israeli funds	2,436		—		2,436
	$	624,646	$	159,397	$	465,249

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.

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2016

Schedule of Inventories

Inventories consist of the following (in thousands):



	December 31,
	2016		2015
Raw materials	$	9,793	$	9,950
Work in process	10,773		7,067
Finished goods	6,565		2,448
Total Inventories	$	27,131	$	19,465

Property, Plant and Equipment

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



		December 31,
	Generally Used Estimated Useful Life	2016			2015
Clinical and manufacturing equipment	Up to 10 years	$	153,938		$	128,044
Computer hardware	3 years	27,978			25,843
Computer software	3 years	59,997			21,451
Furniture and fixtures	5 years	10,306			8,855
Leasehold improvements	Lease term ⁽¹⁾	22,370			20,172
Building	20 years	7,272			4,227
Land	—	3,072			3,072
CIP	—	25,948			42,846
Total		310,881			254,510
Less: Accumulated depreciation and amortization and impairment charges		(135,714		)	(118,037		)
Total Property, plant and equipment, net		$	175,167		$	136,473

⁽¹⁾ Shorter of remaining lease term or estimated useful lives of assets.

Schedule of Accrued Liabilities

Accrued liabilities consist of the following (in thousands):



	December 31,
	2016		2015
Accrued payroll and benefits	$	79,214	$	55,430
Accrued sales and marketing expenses	11,970		7,071
Accrued sales rebate	10,342		8,486
Accrued sales tax and value added tax	5,032		4,801
Accrued income taxes	4,210		2,646
Accrued warranty	3,841		2,638
Accrued professional fees	3,604		2,775
Other accrued liabilities	16,119		23,918
Total Accrued Liabilities	$	134,332	$	107,765

Warranty accrual

Warranty accrual as of December 31, 2016 and 2015 consists of the following activity (in thousands):



Warranty accrual, December 31, 2014	$	3,148
Charged to cost of revenues	1,796
Actual warranty expenditures	(2,306		)
Warranty accrual, December 31, 2015	2,638
Charged to cost of revenues	4,894
Actual warranty expenditures	(3,691		)
Warranty accrual, December 31, 2016	$	3,841

Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The change in the carrying value of goodwill for the year ended December 31, 2016, all attributable to our Clear Aligner reporting unit, is as follows (in thousands):



	Total
Balance as of December 31, 2014	$	61,369
Adjustments ⁽¹⁾	(295		)
Balance as of December 31, 2015	61,074
Adjustments ⁽¹⁾	(30		)
Balance as of December 31, 2016	$	61,044

⁽¹⁾The adjustments to goodwill were a result of foreign currency translation.

Schedule of Amortized Intangible Assets

Acquired intangible long-lived assets are being amortized as follows (in thousands):



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2016		Accumulated Amortization			Accumulated Impairment Loss			Net Carrying Value as of December 31, 2016
Trademarks	15	$	7,100	$	(1,631	)	$	(4,179	)	$	1,290
Existing technology	13	12,600		(4,141		)	(4,328		)	4,131
Customer relationships	11	33,500		(12,819		)	(10,751		)	9,930
Patents	8	6,316		(713		)	—			5,603
Total Intangible Assets		$	59,516	$	(19,304	)	$	(19,258	)	$	20,954



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2015		Accumulated Amortization			Accumulated Impairment Loss			Net Carrying Value as of December 31, 2015
Trademarks	15	$	7,100	$	(1,492	)	$	(4,179	)	$	1,429
Existing technology	13	12,600		(3,577		)	(4,328		)	4,695
Customer relationships	11	33,500		(10,957		)	(10,751		)	11,792
Patents	8	285		(113		)	—			172
Total Intangible Assets		$	53,485	$	(16,139	)	$	(19,258	)	$	18,088

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, 2016 is as follows (in thousands):



Fiscal Year
2017	$	3,355
2018	3,353
2019	3,346
2020	3,336
2021	3,334
Thereafter	4,230
Total	$	20,954

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2016

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, 2016, 2015 and 2014 is as follows (in thousands):



	For the Year Ended December 31,
	2016		2015		2014
Cost of net revenues	$	3,966	$	3,938	$	3,616
Selling, general and administrative	42,612		40,813		29,625
Research and development	7,570		8,192		6,582
Total stock-based compensation	$	54,148	$	52,943	$	39,823

Stock Option Activity

Activity for the year ended December 31, 2016, 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, 2015	496		15.14
Granted	—		—
Exercised	(274	)	15.33
Cancelled or expired	—		—
Outstanding as of December 31, 2016	222		$	14.90	1.12	$	18,058
Vested and expected to vest at December 31, 2016	222		$	14.90	1.12	$	18,058
Exercisable at December 31, 2016	222		$	14.90	1.12	$	18,058

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,
	2016			2015			2014
Expected term (in years)	3			3			3
Expected volatility	34.0		%	36.9		%	46.0		%
Risk-free interest rate	0.9		%	1.0		%	0.7		%
Expected dividends	—			—			—
Weighted average fair value per share at grant date	$	68.88		$	61.73		$	50.46

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 2010 Purchase Plan shares was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:



	Year Ended December 31,
	2016			2015			2014
Expected term (in years)	1.2			1.2			1.2
Expected volatility	30.5		%	31.1		%	38.8		%
Risk-free interest rate	0.7		%	0.3		%	0.2		%
Expected dividends	—			—			—
Weighted average fair value at grant date	$	22.23		$	16.19		$	17.15

Stock Option

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

Activity for the year ended December 31, 2016, 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, 2015	496		15.14
Granted	—		—
Exercised	(274	)	15.33
Cancelled or expired	—		—
Outstanding as of December 31, 2016	222		$	14.90	1.12	$	18,058
Vested and expected to vest at December 31, 2016	222		$	14.90	1.12	$	18,058
Exercisable at December 31, 2016	222		$	14.90	1.12	$	18,058

Restricted Stock Units (RSUs)

Summary of Nonvested Shares

A summary for the year ended December 31, 2016, is as follows (in thousands, except years and per share amounts):



	Shares Underlying RSUs		Weighted Average Grant Date Fair Value		Weighted Remaining Vesting Period (in years)	Aggregate Intrinsic Value
Nonvested as of December 31, 2015	2,079		$	49.45
Granted	714		67.82
Vested and released	(859	)	45.45
Forfeited	(145	)	53.36
Nonvested as of December 31, 2016	1,789		$	58.39	1.12	$	171,934

Market Performance Based Restricted Stock Units

Summary of Nonvested Shares

The following table summarizes the MSU performance as of December 31, 2016:



	Number of Shares Underlying MSUs (in thousands)		Weighted Average Grant Date Fair Value	Weighted Average Remaining Vesting Period (in years )	Aggregate Intrinsic Value (in thousands)
Nonvested as of December 31, 2015	611		51.41
Granted	218		55.77
Vested and released	(270	)	36.73
Forfeited	(39	)	56.41
Nonvested as of December 31, 2016	520		60.49	1.1	$	50,021

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Schedule of Income before Income Tax, Domestic and Foreign

income before provision for income taxes and equity in losses of investee consist of the following (in thousands):



	Year ended December 31,
	2016		2015		2014
Domestic	$	118,871	$	87,803	$	94,784
Foreign	123,695		98,298		95,585
Net income before provision for income taxes and equity in losses of investee	$	242,566	$	186,101	$	190,369

Schedule of Components of Income Tax Expense (Benefit)

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



	Year Ended December 31,
	2016			2015			2014
Federal
Current	$	40,235		$	28,596		$	1,569
Deferred	24,794			6,679			37,570
	65,029			35,275			39,139
State
Current	2,603			3,271			2,162
Deferred	2,636			(703		)	971
	5,239			2,568			3,133
Foreign
Current	8,964			4,305			1,596
Deferred	(28,032		)	(67		)	669
	(19,068		)	4,238			2,265
Provision for income taxes	$	51,200		$	42,081		$	44,537

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 are as follows:



	Year Ended December 31,
	2016		2015		2014
U.S. federal statutory income tax rate	35.0	%	35.0	%	35.0	%
State income taxes, net of federal tax benefit	2.1		1.5		1.6
Impact of differences in foreign tax rates	(6.3	)	(16.2	)	(16.4	)
Valuation allowance release for Israel	(12.9	)	—		—
Stock-based compensation	1.2		1.6		1.0
Other items not individually material	2.0		0.7		2.2
	21.1	%	22.6	%	23.4	%

Schedule of Deferred Tax Assets and Liabilities

As of December 31, 2016 and 2015, the significant components of our deferred tax assets and liabilities are (in thousands):



	Year Ended December 31,
	2016			2015
Deferred tax assets:
Net operating loss and capital loss carryforwards	$	25,445		$	31,247
Reserves and accruals	22,954			17,455
Stock-based compensation	16,399			16,523
Deferred revenue	13,975			24,432
Net translation losses	1,634			649
Credit carryforwards	679			1,932
	81,086			92,238
Deferred tax liabilities:
Depreciation and amortization	12,034			8,555
Prepaid expenses	969			601
	13,003			9,156
Net deferred tax assets before valuation allowance	68,083			83,082
Valuation allowance	(256		)	(31,685		)
Net deferred tax assets	$	67,827		$	51,397

Schedule of Unrecognized Tax Benefits Rollforward

The changes in the balance of gross unrecognized tax benefits, which exclude interest and penalties, for the year ended December 31, 2016, 2015 and 2014, are as follows (in thousands):



Unrecognized tax benefit as of December 31, 2013	$	26,668
Tax positions related to current year:
Additions for uncertain tax positions	6,659
Tax positions related to prior year:
Reductions for uncertain tax positions	(260		)
Unrecognized tax benefit as of December 31, 2014	33,067
Tax positions related to current year:
Additions for uncertain tax positions	6,346
Unrecognized tax benefit as of December 31, 2015	39,413
Tax positions related to current year:
Additions for uncertain tax positions	6,971
Unrecognized tax benefit as of December 31, 2016	$	46,384

Segments and Geographical Information (Tables)

12 Months Ended

Dec. 31, 2016

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment



	For the Year Ended December 31,
Net Revenues	2016			2015			2014
Clear Aligner	$	958,327		$	800,186		$	712,549
Scanner	121,547			45,300			49,104
Total net revenues	$	1,079,874		$	845,486		$	761,653
Gross Profit
Clear Aligner	$	747,494		$	628,187		$	562,889
Scanner	67,800			11,923			15,554
Total gross profit	$	815,294		$	640,110		$	578,443
Income from Operations
Clear Aligner	$	411,817		$	371,113		$	341,055
Scanner	37,498			(12,337		)	(8,483		)
Unallocated corporate expenses	(200,394		)	(170,142		)	(138,996		)
Total income from operations	$	248,921		$	188,634		$	193,576
Depreciation and Amortization
Clear Aligner	$	13,742		$	9,842		$	8,706
Scanner	3,871			3,839			4,498
Unallocated corporate expenses	6,389			4,323			4,652
Total depreciation and amortization	$	24,002		$	18,004		$	17,856

The following table reconciles total segment income from operations in the table above to net income before provision for income taxes and equity losses of investee:



	For the Year Ended December 31,
	2016			2015			2014
Total segment income from operations	$	449,315		$	358,776		$	332,572
Unallocated corporate expenses	(200,394		)	(170,142		)	(138,996		)
Total income from operations	248,921			188,634			193,576
Interest and other income (expense), net	(6,355		)	(2,533		)	(3,207		)
Net income before provision for income taxes and equity losses of investee	$	242,566		$	186,101		$	190,369

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

Net revenues are presented below by geographic area (in thousands):



	For the Year Ended December 31,
	2016		2015		2014
Net revenues⁽¹⁾:
United States ⁽²⁾	$	692,254	$	585,874	$	532,569
The Netherlands ⁽²⁾	291,053		167,128		156,817
Other International	96,567		92,484		72,267
Total net revenues	$	1,079,874	$	845,486	$	761,653


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

⁽²⁾ During 2016, we implemented a new international corporate structure. This changed the structure of our international procurement and sales operations.

Tangible long-lived assets are presented below by geographic area (in thousands):



	As of December 31,
	2016		2015
Long-lived assets ⁽¹⁾:
The Netherlands ⁽²⁾	$	111,515	$	486
United States ⁽²⁾	43,278		112,632
Mexico	17,918		15,422
Other International	2,456		7,933
Total long-lived assets	$	175,167	$	136,473

⁽¹⁾ Long-lived assets are attributed to countries based on entity that owns the assets.

⁽²⁾ As a result of the new international corporate structure changes, approximately $92.0 million in long-lived assets were transferred from the U.S. to our Netherlands entity in 2016.

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) segment stage financial_institution aligner	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Significant Accounting Policies [Line Items]
Number of operating segments \| segment	2
Restricted Cash and Cash Equivalents	$ 3.7	$ 3.5
Original maturity of highly liquid investments included in Cash and cash equivalents	27 months
Foreign currency net loss	$ 8.0	4.0
Number of financial instutions used \| financial_institution	2
Capitalized software costs	$ 13.2	25.4
Scanners, Warranty period	1 year
Treatment Plans, Period For Additional Replacements For No Charge	5 years
Treatment Plans, Number Of Optional Replacements \| aligner	6
Treatment Plan, Number Of Batches/Stages \| stage	9
Advertising cost	$ 36.0	23.4	$ 26.9
Lease term	9 years
Undistributed earnings of foreign subsidiaries	$ 438.0
Minimum
Significant Accounting Policies [Line Items]
Estimated useful lives of intangibles	1 year
Maximum
Significant Accounting Policies [Line Items]
Original maturity of highly liquid investments included in Cash and cash equivalents	3 months
Estimated useful lives of intangibles	15 years
Noncurrent Assets
Significant Accounting Policies [Line Items]
Restricted cash		3.7
Other Noncurrent Assets
Significant Accounting Policies [Line Items]
Restricted cash	$ 3.3	3.3
Prepaid Expenses and Other Current Assets
Significant Accounting Policies [Line Items]
Restricted cash		3.5
Other Current Assets
Significant Accounting Policies [Line Items]
Restricted cash	$ 0.4	$ 0.2

Summary of Significant Accounting Policies - Out of period adjustment (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Error Corrections and Prior Period Adjustments Restatement [Line Items]

Provision for income taxes

^[1]

$ (1,079,874)

$ (845,486)

$ (761,653)

Operating expenses

566,373

451,476

384,867

51,200

42,081

44,537

Net income

$ 189,682

$ 144,020

145,832

Out Of Period Correction [Member]

Error Corrections and Prior Period Adjustments Restatement [Line Items]

Provision for income taxes

$ 1,800

[1]	1) Long-lived assets are attributed to countries based on entity that owns the assets.(2) As a result of the new international corporate structure changes, approximately $92.0 million in long-lived assets were transferred from the U.S. to our Netherlands entity in 2016.

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

Balance, Beginning Balance

Marketable Securities and Fair Value Measurements - Short-term and Long-term Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 251,086	$ 359,956
Gross Unrealized Gains	38	14
Gross Unrealized Losses	(143)	(389)
Fair Value	250,981	359,581
Short-term Investments \| Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	42,397	38,537
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(6)	0
Fair Value	42,391	38,537
Short-term Investments \| Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	122,788	179,765
Gross Unrealized Gains	22	6
Gross Unrealized Losses	(121)	(251)
Fair Value	122,689	179,520
Short-term Investments \| U.S. dollar dominated foreign corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		510
Gross Unrealized Gains		0
Gross Unrealized Losses		(2)
Fair Value		508
Short-term Investments \| Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,852	14,209
Gross Unrealized Gains	0	7
Gross Unrealized Losses	(5)	(2)
Fair Value	5,847	14,214
Short-term Investments \| U.S. government agency bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	28,903	75,172
Gross Unrealized Gains	9	0
Gross Unrealized Losses	(4)	(53)
Fair Value	28,908	75,119
Short-term Investments \| Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	45,146	51,763
Gross Unrealized Gains	7	1
Gross Unrealized Losses	(7)	(81)
Fair Value	45,146	51,683
Short-term Investments \| Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,000
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	6,000
Long Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	59,887	151,869
Gross Unrealized Gains	13	9
Gross Unrealized Losses	(117)	(508)
Fair Value	59,783	151,370
Long Term Investments \| Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	40,889	64,012
Gross Unrealized Gains	8	9
Gross Unrealized Losses	(85)	(218)
Fair Value	40,812	63,803
Long Term Investments \| Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		3,993
Gross Unrealized Gains		0
Gross Unrealized Losses		(2)
Fair Value		3,991
Long Term Investments \| Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	177	2,338
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(3)
Fair Value	177	2,335
Long Term Investments \| US Government Agency Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,805	43,853
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(16)	(178)
Fair Value	6,789	43,675
Long Term Investments \| U.S. Government Treasury Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	12,016	37,673
Gross Unrealized Gains	5	0
Gross Unrealized Losses	(16)	(107)
Fair Value	$ 12,005	$ 37,566

Marketable Securities and Fair Value Measurements - Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Investments, All Other Investments [Abstract]
One year or less	$ 250,981	$ 359,581
One year through two years	59,783	151,370
Marketable Securities	$ 310,764	$ 510,951

Marketable Securities and Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
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	27 months
Weighted average maturity	7 months	9 months
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term notes receivable	$ 2,000
Gain on notes receivable	50
Fair value	$ 2,050

Balance Sheet Components - Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 9,793	$ 9,950
Work in process	10,773	7,067
Finished goods	6,565	2,448
Inventories	$ 27,131	$ 19,465

Balance Sheet Components - Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment, Net [Abstract]
Property and equipment	$ 310,881	$ 254,510
Less: Accumulated depreciation and amortization	(135,714)	(118,037)
Property, plant and equipment, net	175,167	136,473
Depreciation and amortization	24,000	18,000	$ 17,900
Clinical and manufacturing equipment
Property, Plant and Equipment, Net [Abstract]
Property and equipment	153,938	128,044
Computer hardware
Property, Plant and Equipment, Net [Abstract]
Property and equipment	27,978	25,843
Computer software
Property, Plant and Equipment, Net [Abstract]
Property and equipment	59,997	21,451
Furniture and fixtures
Property, Plant and Equipment, Net [Abstract]
Property and equipment	10,306	8,855
Leasehold improvements
Property, Plant and Equipment, Net [Abstract]
Property and equipment	22,370	20,172
Building
Property, Plant and Equipment, Net [Abstract]
Property and equipment	7,272	4,227
Land
Property, Plant and Equipment, Net [Abstract]
Property and equipment	3,072	3,072
Construction in progress
Property, Plant and Equipment, Net [Abstract]
Property and equipment	$ 25,948	$ 42,846

Balance Sheet Components - Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Accrued payroll and benefits	$ 79,214	$ 55,430
Accrued sales rebate	10,342	8,486
Accrued sales tax and value added tax	5,032	4,801
Accrued sales and marketing expenses	11,970	7,071
Accrued warranty	3,841	2,638
Accrued professional fees	3,604	2,775
Accrued income taxes	4,210	2,646
Other	16,119	23,918
Total current accrued liabilities	$ 134,332	$ 107,765

Balance Sheet Components - Warranty Accrual Activity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 2,638	$ 3,148
Charged to cost of revenues	4,894	1,796
Actual warranty expenditures	(3,691)	(2,306)
Balance at end of period	$ 3,841	$ 2,638

Equity Method Investments (Details) - USD ($) $ in Thousands		12 Months Ended
	Jul. 25, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]
Ownership	17.00%
Payments to acquire	$ 46,700	$ 46,745	$ 0	$ 0
Equity method investment		$ 45,061	$ 0

Goodwill and Intangible Assets - Change in the Carrying Value of Goodwill (Detail) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2016

Dec. 31, 2015

Goodwill [Roll Forward]

$ 61,074

$ 61,369

Goodwill, Translation Adjustments

(30)

(295)

^[1]

Balance, Ending Balance

$ 61,044

$ 61,074

[1]	The adjustments to goodwill were a result of foreign currency translation.

Goodwill and Intangible Assets - Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 59,516	$ 53,485
Accumulated Amortization	(19,304)	(16,139)
Accumulated Impairment Loss	(19,258)	(19,258)
Total	$ 20,954	$ 18,088
Trademarks
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles	15 years	15 years
Gross Carrying Amount	$ 7,100	$ 7,100
Accumulated Amortization	(1,631)	(1,492)
Accumulated Impairment Loss	(4,179)	(4,179)
Total	$ 1,290	$ 1,429
Existing technology
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles	13 years	13 years
Gross Carrying Amount	$ 12,600	$ 12,600
Accumulated Amortization	(4,141)	(3,577)
Accumulated Impairment Loss	(4,328)	(4,328)
Total	$ 4,131	$ 4,695
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles	11 years	11 years
Gross Carrying Amount	$ 33,500	$ 33,500
Accumulated Amortization	(12,819)	(10,957)
Accumulated Impairment Loss	(10,751)	(10,751)
Total	$ 9,930	$ 11,792
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles	8 years	8 years
Gross Carrying Amount	$ 6,316	$ 285
Accumulated Amortization	(713)	(113)
Accumulated Impairment Loss	0	0
Total	$ 5,603	$ 172

Goodwill and Intangible Assets - Total Estimated Annual Future Amortization Expense for the Acquired Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
2014	$ 3,355
2015	3,353
2016	3,346
2017	3,336
2018	3,334
Thereafter	4,230
Total	$ 20,954	$ 18,088

Credit Facilities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	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

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions		12 Months Ended
	Jul. 25, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 19, 2016
Other Commitments [Line Items]
Loans And Leases Receivable, Commitments, Fixed Rates, State Rate	7.00%
Total rent expense		$ 9.9	$ 8.2	$ 7.6
Commitments To Purchase Convertible Promissory Notes With Privately Held Company [Member]
Other Commitments [Line Items]
Other commitment		5.0
Other Commitments, Future Minimum Payments, Remainder of Fiscal Year		2.0
Other Commitment, Due in Second Year		$ 3.0
Debt Instrument, Interest Rate, Stated Percentage		2.50%
Purchase Of Real Esteate From LBA RIV
Other Commitments [Line Items]
Other commitment					$ 44.1
Escrow deposit		$ 1.0
SDC [Member]
Other Commitments [Line Items]
Loans And Leases Receivable, Borrowing Base As A Percentage Of Accounts Receivable	80.00%
Maximum \| SDC [Member]
Other Commitments [Line Items]
Loans and Leases Receivable, Commitments, Fixed Rates	$ 15.0

Commitments and Contingencies - Minimum Future Lease Payments for Non-Cancelable Leases (Detail) $ in Thousands	Dec. 31, 2016 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2017	$ 12,880
2018	10,338
2019	8,466
2020	6,849
2021	6,247
Thereafter	9,141
Total minimum lease payments	$ 53,921

Stockholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) purchase_period $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	May 16, 2013 shares
Stockholders Equity Note [Line Items]
Preferred stock, par value (usd per share) \| $ / shares	$ 0.0001	$ 0.0001
Total intrinsic value of stock options exercised \| $	$ 18,200	$ 7,400	$ 24,500
Employees’ taxes paid upon the vesting of restricted stock units \| $	$ (29,857)	(20,716)	(7,608)
Employee Stock Purchase Plan, Duration Of Offering Period	24 months
Number of offering periods \| purchase_period	4
Stock-based compensation expense \| $	$ 54,148	52,943	39,823
Stockholder Rights Plan
Stockholders Equity Note [Line Items]
Number of shares called by each right (shares)	0.001
Amended And Restated 2005 Stock Incentive Plan
Stockholders Equity Note [Line Items]
Shares reserved for issuance	8,023,709
2001 Purchase Plan
Stockholders Equity Note [Line Items]
Employee stock purchase plan, purchase price as percentage of fair market value of common stock	85.00%
Restricted Stock Units (RSUs)
Stockholders Equity Note [Line Items]
Vested rand released in period, Total intrinsic value \| $	$ 59,800	45,900	38,900
Vested in period, Fair value \| $	$ 39,100	$ 30,000	$ 22,000
Granted (usd per share) \| $ / shares	$ 67.82	$ 57.78	$ 53.72
Total unamortized compensation cost \| $	$ 63,300
Weighted average period of total unamortized cost	2 years
Restricted stock units, shares vested and released (shares)	859,410
Restricted stock units, shares withheld for tax payments	300,031
Restricted stock units, net issuance	559,379
Stock Options \| Incentive Plan 2005
Stockholders Equity Note [Line Items]
Weighted award against authorized maximum (shares)	25% vesting one year from the date of grant and 1/48th each month thereafter
Market Performance Based Restricted Stock Units
Stockholders Equity Note [Line Items]
Vested rand released in period, Total intrinsic value \| $	$ 17,400	$ 9,200	$ 2,900
Vested in period, Fair value \| $	$ 9,900	$ 4,900	$ 1,200
Granted (usd per share) \| $ / shares	$ 55.77
Total unamortized compensation cost \| $	$ 11,100
Weighted average period of total unamortized cost	1 year 1 month 6 days
Restricted stock units, shares vested and released (shares)	270,347
Restricted stock units, shares withheld for tax payments	136,758
Restricted stock units, net issuance	133,589
Market Performance Based Restricted Stock Units \| Minimum
Stockholders Equity Note [Line Items]
Stock incentive plan, vesting period	2 years
Market Performance Based Restricted Stock Units \| Maximum
Stockholders Equity Note [Line Items]
Stock incentive plan, vesting period	3 years
Percentage of market-performance based restricted stock units eligible to vest over the vesting period	150.00%
Employee Stock Incentive Plan 2005 [Member]
Stockholders Equity Note [Line Items]
Added to pool (shares)	4,500,000	0
Number of shares available for grant (shares)				27,783,379
Share-based Compensation Arrangement by Share-based Payment Award, Weight Of Awarded Shares Against Authorized Maximum	1.9			1.5
Employee Stock Purchase Plan 2010
Stockholders Equity Note [Line Items]
Employee stock purchase plan, shares issued	196,882	230,078	247,343
Weighted average exercise price (usd per share) \| $ / shares	$ 48.65	$ 36.66	$ 29.24
Number of shares available for grant (shares)	936,867
Employee Stock Purchase Plan 2010 \| Maximum
Stockholders Equity Note [Line Items]
Maximum number of shares available	2,400,000
Employee Stock Purchase Plan
Stockholders Equity Note [Line Items]
Total unamortized compensation cost \| $	$ 700
Weighted average period of total unamortized cost	3 months 18 days
Stock-based compensation expense \| $	$ 2,700	$ 4,100	$ 2,600
Monthly Vesting \| Stock Options \| Incentive Plan 2005
Stockholders Equity Note [Line Items]
Stock incentive plan, vesting percentage	2.08%

Stockholders' Equity - Stock-Based Awards and Employee Stock Purchases (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 54,148	$ 52,943	$ 39,823
Cost of revenues
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	3,966	3,938	3,616
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	42,612	40,813	29,625
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 7,570	$ 8,192	$ 6,582

Stockholders' Equity - Activity Under Stock Option Plans (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Number of Shares Underlying Stock Options
Outstanding beginning balance (shares) \| shares	496
Granted (shares) \| shares	0
Exercised (shares) \| shares	(274)
Cancelled or expired (shares) \| shares	0
Outstanding ending balance (shares) \| shares	222
Vested and expected to vest at December 31, 2013 (shares) \| shares	222
Exercisable at December 31, 2013 (shares) \| shares	222
Weighted Average Exercise Price per Share
Outstanding beginning balance (usd per share) \| $ / shares	$ 15.14
Granted (usd per share) \| $ / shares	0.00
Exercised (usd per share) \| $ / shares	15.33
Cancelled or expired (usd per share) \| $ / shares	0.00
Outstanding ending balance (usd per share) \| $ / shares	14.90
Vested and expected to vest at December 31, 2013 (usd per share) \| $ / shares	14.90
Exercisable at December 31, 2013 (usd per share) \| $ / shares	$ 14.90
Weighted Average Remaining Contractual Term (in years)
Outstanding as of December 31, 2016	1 year 1 month 13 days
Vested and expected to vest at December 31, 2016	1 year 1 month 13 days
Exercisable at December 31, 2016	1 year 1 month 13 days
Aggregate Intrinsic Value
Outstanding as of December 31, 2016 \| $	$ 18,058
Vested and expected to vest at December 31, 2016 \| $	18,058
Exercisable at December 31, 2016 \| $	$ 18,058

Stockholders' Equity - Summary of Nonvested Shares (Detail) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Shares Underlying RSUs
Nonvested beginning balance (shares)	2,079,000
Granted (shares)	714,000
Vested and released (shares)	(859,410)
Forfeited (shares)	(145,000)
Nonvested ending balance (shares)	1,789,000	2,079,000
Nonvested, beginning balance (usd per share)	$ 49.45
Granted (usd per share)	67.82	$ 57.78	$ 53.72
Vested and released (usd per share)	45.45
Forfeited (usd per share)	53.36
Nonvested, ending balance (usd per share)	$ 58.39	$ 49.45
Weighted Remaining Vesting Period (in years)
Nonvested as of December 31, 2016	1 year 1 month 13 days
Aggregate Intrinsic Value
Nonvested as of December 31, 2016	$ 171,934

Stockholders' Equity - Summary of MSU Performance (Detail) - Market Performance Based Restricted Stock Units - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Number of Shares
Nonvested beginning balance (shares)	611,000
Granted (shares)	218,000
Vested and released (shares)	(270,347)
Forfeited (shares)	(39,000)
Nonvested ending balance (shares)	520,000	611,000
Nonvested (usd per share)	$ 60.49	$ 51.41
Granted (usd per share)	55.77
Vested and released (usd per share)	36.73
Forfeited (usd per share)	$ 56.41
Weighted Average Remaining Contractual Term
Nonvested	1 year 1 month 6 days
Aggregate Intrinsic Value
Nonvested	$ 50,021

Stockholders' Equity - Weighted-Average Assumptions Used in the Monte Carlo Simulation (Detail) - Market Performance Based Restricted Stock Units - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	3 years	3 years	3 years
Expected volatility	34.00%	36.90%	46.00%
Risk-free interest rate	0.90%	1.00%	0.70%
Expected dividends	0.00%	0.00%	0.00%
Weighted average fair value per share at grant date (usd per share)	$ 68.88	$ 61.73	$ 50.46

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 - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
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 2 months 12 days
Expected volatility	30.50%	31.10%	38.80%
Risk-free interest rate	0.70%	0.30%	0.20%
Expected dividends	0.00%	0.00%	0.00%
Weighted average fair value at grant date (usd per share)	$ 22.23	$ 16.19	$ 17.15

Common Stock Repurchase Program - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions						3 Months Ended		4 Months Ended	12 Months Ended
	May 04, 2016	Apr. 28, 2015	Jul. 29, 2014	Apr. 28, 2014	Apr. 23, 2014	Jul. 23, 2015	Jul. 29, 2014	Sep. 06, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Apr. 28, 2016
Share Repurchases [Line Items]
Common stock repurchased and retired									$ 96,218,000	$ 101,791,000	$ 98,233,000
Additional Paid-in Capital
Share Repurchases [Line Items]
Common stock repurchased and retired									10,593,000	15,669,000	17,804,000
Retained Earnings
Share Repurchases [Line Items]
Common stock repurchased and retired									$ 85,625,000	$ 86,122,000	$ 80,429,000
April 2014 Stock Repurchase Program
Share Repurchases [Line Items]
Repurchase of common stock, common stock authorized					$ 300,000,000
Repurchase period					3 years
Common stock repurchased and retired (shares)									0.5	0.5	0.6
Common stock repurchased (in dollars per share)									$ 92.58	$ 58.89	$ 50.93
Common stock repurchased and retired									$ 46,200,000	$ 31,800,000	$ 28,200,000
Authorized repurchase amount remaining									$ 3,800,000
Accelerated share repurchase agreement amount	$ 50,000,000	$ 70,000,000		$ 70,000,000
Accelerated share repurchase (in shares)						1.2	1.4	0.6
Accelerated share repurchases price per share (in dollars per share)			$ 51.46			$ 60.52		$ 81.89
April 2016 Stock Repurchase Program [Member]
Share Repurchases [Line Items]
Repurchase of common stock, common stock authorized												$ 300,000,000

Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2009
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Accrued severance funds liability	$ 3.1	$ 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 matching contribution as percentage of employee's eligible compensation				6.00%
Employer contributions amount	$ 3.4	$ 2.7	$ 2.2

Income Taxes - Domestic and Foreign Components of Income (loss) Before Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Domestic	$ 118,871	$ 87,803	$ 94,784
Foreign	123,695	98,298	95,585
Net income before provision for income taxes and equity in losses of investee	$ 242,566	$ 186,101	$ 190,369

Income Taxes Income Taxes - Provision for (Benefit from) Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Federal
Current	$ 40,235	$ 28,596	$ 1,569
Deferred	24,794	6,679	37,570
Total federal income tax expense	65,029	35,275	39,139
State
Current	2,603	3,271	2,162
Deferred	2,636	(703)	971
Total state tax expense	5,239	2,568	3,133
Foreign
Current	8,964	4,305	1,596
Deferred	(28,032)	(67)	669
Total foreign tax expense	(19,068)	4,238	2,265
Provision for income taxes	$ 51,200	$ 42,081	$ 44,537

Income Taxes - Differences Between Income Taxes Using Federal Statutory Income Tax Rate and Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
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	2.10%	1.50%	1.60%
Impact of differences in foreign tax rates	(6.30%)	(16.20%)	(16.40%)
Goodwill Impairment	(12.90%)	0.00%	0.00%
Amortization of stock-based compensation	1.20%	1.60%	1.00%
Other items not individually material	2.00%	0.70%	2.20%
Effective Income Tax Rate, Continuing Operations, Total	21.10%	22.60%	23.40%

Income Taxes Income Taxes - Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating loss and capital loss carryforwards	$ 25,445	$ 31,247
Credit carryforwards	679	1,932
Reserves and accruals	22,954	17,455
Translation gains	1,634	649
Stock-based compensation	16,399	16,523
Deferred Tax Assets, Deferred Income	13,975	24,432
Total deferred tax assets, gross	81,086	92,238
Deferred tax liabilities:
Prepaid expenses	969	601
Depreciation and amortization	12,034	8,555
Total deferred tax liabilities, gross	13,003	9,156
Net deferred tax assets before valuation allowance	68,083	83,082
Valuation allowance	(256)	(31,685)
Net deferred tax assets	$ 67,827	$ 51,397

Income Taxes - Rollforward of Total Gross Unrecognized Tax Benefit (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefit as of beginning of period	$ 39,413	$ 33,067	$ 26,668
Tax positions related to current year, additions for uncertain tax positions	6,971	6,346	6,659
Tax positions related to prior year			(260)
Unrecognized tax benefit as of end of period	$ 46,384	$ 39,413	$ 33,067

Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jun. 30, 2009	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Undistributed earnings of foreign subsidiaries		$ 438,000
Deferred tax assets, valuation allowance		256	$ 31,685
Change in valuation allowance		(31,400)
Increase in unrecognized tax benefits		7,000
Unrecognized tax benefits		46,384	39,413	$ 33,067	$ 26,668
Interest and penalties expense		1,400	1,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued		2,100	700
Expense related to restructuring		34,300
State and Local Jurisdiction
Income Taxes [Line Items]
Net operating loss carryforwards		3,700
Foreign Country
Income Taxes [Line Items]
Net operating loss carryforwards		$ 104,300
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		$ 19,100	$ 32,700	$ 32,500
Tax benefit of tax holiday on net income per share (diluted) (usd per share)		$ 0.23	$ 0.40

Net Profit per Share - Computation of Basic and Diluted Net Profit Per Share Attributable to Common Stock (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net income	$ 189,682	$ 144,020	$ 145,832
Denominator:
Weighted-average common shares outstanding, basic (shares)	79,856	79,998	80,754
Dilutive effect of potential common stock (shares)	1,628	1,523	1,529
Total shares, diluted (shares)	81,484	81,521	82,283
Net income per share, basic (usd per share)	$ 2.38	$ 1.80	$ 1.81
Net income per share, diluted (usd per share)	$ 2.33	$ 1.77	$ 1.77

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

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

Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Cash Flow Information [Abstract]
Taxes paid	$ 47,289	$ 40,621	$ 5,666
Non-cash investing and financing activities:
Fixed assets acquired with accounts payable or accrued liabilities	$ 4,434	$ 14,636	$ 4,899

Segments and Geographical Information Segments and Geographical Information - (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Revenue

^[1]

$ 1,079,874

$ 845,486

$ 761,653

815,294

640,110

578,443

248,921

188,634

193,576

24,002

18,004

17,856

Clear Aligner

Revenue

958,327

800,186

712,549

Scanner and Services

Revenue

121,547

45,300

49,104

Clear Aligner

747,494

628,187

562,889

411,817

371,113

341,055

13,742

9,842

8,706

Scanners And Services

67,800

11,923

15,554

37,498

(12,337)

(8,483)

Corporate, Non-Segment [Member]

3,871

3,839

4,498

(200,394)

(170,142)

(138,996)

$ 6,389

$ 4,323

$ 4,652

[1]	1) Long-lived assets are attributed to countries based on entity that owns the assets.(2) As a result of the new international corporate structure changes, approximately $92.0 million in long-lived assets were transferred from the U.S. to our Netherlands entity in 2016.

Segments and Geographical Information - Net Revenues by Geographic Area (Detail) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Interest and other income (expense), net

$ 248,921

$ 188,634

$ 193,576

(6,355)

(2,533)

(3,207)

Net income before provision for income taxes and equity in losses of investee

242,566

186,101

190,369

^[1]

1,079,874

845,486

761,653

United States

^[1]

692,254

585,874

532,569

the Netherlands

^[1]

291,053

167,128

156,817

Other international

Corporate, Non-Segment [Member]

^[1]

96,567

92,484

72,267

Operating Segments [Member]

(200,394)

(170,142)

(138,996)

$ 449,315

$ 358,776

$ 332,572

[1]	1) Long-lived assets are attributed to countries based on entity that owns the assets.(2) As a result of the new international corporate structure changes, approximately $92.0 million in long-lived assets were transferred from the U.S. to our Netherlands entity in 2016.

Segments and Geographical Information - Long-Lived Assets by Geographic Area (Detail) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2016

Dec. 31, 2015

^[1]

$ 175,167

$ 136,473

United States

^[1]

43,278

112,632

Mexico

^[1]

17,918

15,422

the Netherlands

Long-lived assets transferred

^[1]

111,515

486

^[1]

92,000

Other international