Document and Entity Information	3 Months Ended
Document and Entity Information	Mar. 31, 2015	Apr. 24, 2015
Document Information [Line Items]
Trading Symbol	ALGN
Entity Registrant Name	ALIGN TECHNOLOGY INC
Entity Central Index Key	0001097149
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		80,750,207

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)
In Thousands, except Per Share data, unless otherwise specified

3 Months Ended

Mar. 31, 2015

Mar. 31, 2014

Income Statement [Abstract]

Net revenues

$ 198,086

^[1]

$ 180,646

^[1]

Cost of net revenues

46,996

43,395

Gross profit

151,090

137,251

Operating expenses:

Selling, general and administrative

88,281

82,067

Research and development

13,885

13,380

Total operating expenses

102,166

95,447

Income from operations

48,924

41,804

Interest and other income (expenses), net

(1,452)

601

Net income before provision for income taxes

47,472

42,405

Provision for income taxes

11,295

9,961

Net income

$ 36,177

$ 32,444

Net income per share:

Basic (in usd per share)

$ 0.45

$ 0.40

Diluted (in usd per share)

$ 0.44

$ 0.39

Shares used in computing net income per share:

Basic (in shares)

80,459

81,120

Diluted (in shares)

81,824

82,817

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

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 36,177	$ 32,444
Net change in cumulative translation adjustment	(261)	106
Change in unrealized gains (losses) on available-for-sale securities, net of tax	295	42
Other comprehensive income	34	148
Comprehensive income	$ 36,211	$ 32,592

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 189,978	$ 199,871
Marketable securities, short-term	254,823	254,787
Accounts receivable, net of allowances for doubtful accounts and returns of $1,461 and $1,563, respectively	138,159	129,751
Inventories	14,572	15,928
Prepaid expenses and other current assets	29,869	19,770
Deferred Tax Assets, Net, Current	29,911	37,053
Total current assets	657,312	657,160
Marketable securities, long-term	168,171	147,892
Property, plant and equipment, net	99,764	90,125
Goodwill and intangible assets, net	81,274	82,056
Deferred tax assets	14,630	3,099
Other assets	7,254	7,665
Total assets	1,028,405	987,997
Current liabilities:
Accounts payable	24,996	23,247
Accrued liabilities	81,711	87,880
Deferred revenues	93,868	90,684
Total current liabilities	200,575	201,811
Taxes Payable	31,831	30,483
Other long-term liabilities	2,465	2,932
Total liabilities	234,871	235,226
Commitments and contingencies (Note 6 and 7)
Stockholders' equity:
Preferred stock, $0.0001 par value (5,000 shares authorized; none issued)	0	0
Common stock, $0.0001 par value (200,000 shares authorized; 80,734 and 80,205 issued and outstanding, respectively)	8	8
Additional paid-in capital	789,453	783,410
Accumulated other comprehensive loss, net	(106)	(140)
Retained Earnings (accumulated deficit)	4,179	(30,507)
Total stockholders’ equity	793,534	752,771
Total liabilities and stockholders’ equity	$ 1,028,405	$ 987,997

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Accounts receivable, allowance for doubtful accounts and returns	$ 1,461	$ 1,563
Preferred stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	0
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000	200,000
Common stock, shares issued	80,734	80,205
Common stock, shares outstanding	80,734	80,205

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 36,177	$ 32,444
Adjustments to reconcile net profit to net cash provided by operating activities:
Deferred taxes	291	12,769
Depreciation and amortization	4,308	4,776
Stock-based compensation	11,648	9,132
Excess tax benefit from share-based payment arrangements	(4,779)	(13,568)
Other non-cash operating activities	2,614	1,977
Changes in assets and liabilities, net of acquired assets and liabilities:
Accounts receivable	(12,233)	(13,939)
Inventories	1,334	(1,870)
Prepaid expenses and other assets	(10,527)	(1,790)
Accounts payable	1,871	265
Accrued and other long-term liabilities	(1,078)	(15,286)
Deferred revenues	6,019	3,083
Net cash provided by operating activities	35,645	17,993
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(15,612)	(4,996)
Purchase of marketable securities	(113,508)	(157,919)
Proceeds from maturities of marketable securities	86,908	53,137
Proceeds from sales of marketable securities	5,505	10,564
Other investing activities	46	(133)
Net cash used in investing activities	(36,661)	(99,347)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	4,552	11,946
Common stock repurchases	(1,781)	0
Excess tax benefit from share-based payment arrangements	4,779	13,568
Employees’ taxes paid upon the vesting of restricted stock units	(14,647)	(4,453)
Net cash (used in) provided by financing activities	(7,097)	21,061
Effect of foreign exchange rate changes on cash and cash equivalents	(1,780)	106
Net decrease in cash and cash equivalents	(9,893)	(60,187)
Cash and cash equivalents, beginning of the period	199,871	242,953
Cash and cash equivalents, end of the period	$ 189,978	$ 182,766

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2015
Notes To Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of presentation The accompanying unaudited Condensed Consolidated Financial Statements have been prepared by Align Technology, Inc. (“we”, “our”, or “Align”) in accordance with the rules and regulations of the Securities and Exchange Commission ("SEC") and contain all adjustments, including normal recurring adjustments, necessary to present fairly our results of operations for the three months ended March 31, 2015 and 2014, our comprehensive income for the three months ended March 31, 2015 and 2014, our financial position as of March 31, 2015 and our cash flows for the three months ended March 31, 2015 and 2014. The Condensed Consolidated Balance Sheet as of December 31, 2014 was derived from the December 31, 2014 audited financial statements. Net revenues by geographic area for prior period amounts in Note 13 have been reclassified to conform with the current period presentation. These reclassifications had no impact on our financial position for the three months ended March 31, 2015 and 2014. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 or any other future period, and we make no representations related thereto. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” “Quantitative and Qualitative Disclosures About Market Risk” and the Consolidated Financial Statements and notes thereto included in Items 7, 7A and 8, respectively, in our Annual Report on Form 10-K for the year ended December 31, 2014. 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, useful lives of intangible assets and property and equipment, revenue recognition, stock-based compensation, 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. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2014-09, “Revenue from Contracts with Customers,” requiring an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The updated standard will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective and permits the use of either the retrospective or cumulative effect transition method. We expect the updated standard to become effective for us in the first quarter of fiscal 2018. We have not yet selected a transition method and we are currently evaluating the effect that the updated standard will have on our consolidated financial statements and related disclosures. In April 2015, the FASB issued ASU No. 2015-05, "Customer's Accounting for Fees Paid in a Cloud Computing Arrangement." providing guidance to entities about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the entity should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the entity should account for the arrangement as a service contract. The new guidance does not change the accounting for an entity's accounting for service contracts. The updated standard becomes effective for interim and annual reporting periods beginning after December 15, 2015. We are currently evaluating the effect that the updated standard will have on our consolidated financial statements and related disclosures.

Marketable Securities and Fair Value Measurements

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

Marketable Securities and Fair Value Measurements

Note 2. Marketable Securities and Fair Value Measurements

As of March 31, 2015 and December 31, 2014, 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



March 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	16,774	$	—	$	—		$	16,774
Corporate bonds	144,230		31		(71		)	144,190
Municipal securities	11,310		9		—			11,319
U.S. government agency bonds	60,342		20		(4		)	60,358
U.S. government treasury bonds	17,772		12		—			17,784
Certificates of deposit	1,399		—		—			1,399
Agency discount notes	2,998		1		—			2,999
Total Marketable Securities, Short-Term	$	254,825	$	73	$	(75	)	$	254,823

Long-term



March 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	50,542	$	50	$	(5	)	$	50,587
Corporate bonds	66,738		30		(45		)	66,723
U.S. dollar dominated foreign corporate bonds	520		—		—			520
U.S. government treasury bonds	33,310		70		—			33,380
Municipal securities	6,425		10		(1		)	6,434
Asset-backed securities	10,533		—		(6		)	10,527
Total Marketable Securities, Long-Term	$	168,068	$	160	$	(57	)	$	168,171

Short-term



December 31, 2014	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	33,998	$	—	$	—		$	33,998
Corporate bonds	152,055		27		(116		)	151,966
U.S. dollar dominated foreign corporate bonds	901		—		—			901
Municipal securities	9,147		13		—			9,160
U.S. government agency bonds	41,574		14		(1		)	41,587
U.S. government treasury bonds	15,770		7		—			15,777
Certificates of Deposits	1,398		—		—			1,398
Total Marketable Securities, Short-Term	$	254,843	$	61	$	(117	)	$	254,787

Long-term



December 31, 2014	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	48,233	$	12	$	(28	)	$	48,217
Corporate bonds	57,195		6		(112		)	57,089
U.S. dollar dominated foreign corporate bonds	523		—		(2		)	521
U.S. government treasury bonds	20,814		5		(6		)	20,813
Municipal securities	9,552		5		(6		)	9,551
Asset-backed securities	11,713		—		(12		)	11,701
Total Marketable Securities, Long-Term	$	148,030	$	28	$	(166	)	$	147,892

For the three months ended March 31, 2015 and 2014, realized gains were immaterial. Unrealized gains and losses for our available for sale securities as of March 31, 2015 and December 31, 2014 were also immaterial. Cash and cash equivalents are not included in the table above as the gross unrealized gains and losses are not material. We have no material short-term or long-term investments that have been in a continuous unrealized loss position for greater than twelve months as of March 31, 2015 and December 31, 2014. Amounts reclassified to earnings from accumulated other comprehensive income related to unrealized gain or losses were immaterial for the three months ended March 31, 2015 and 2014.

Our fixed-income securities investment portfolio consists of corporate bonds, U.S. dollar dominated foreign corporate bonds, commercial paper, municipal securities, U.S. government agency bonds, U.S. government treasury bonds, certificates of deposit, agency discount notes and asset-backed securities that have a maximum 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 11 months as of March 31, 2015 and December 31, 2014, 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 March 31, 2015 and December 31, 2014 (in thousands):



	March 31,		December 31,
	2015		2014
Due in one year or less	$	254,823	$	254,787
Due in greater than one year	168,171		147,892
Total available for sale short-term and long-term marketable securities	$	422,994	$	402,679

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 March 31, 2015 or December 31, 2014.

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

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

We did not hold any Level 2 liabilities as of March 31, 2015 or December 31, 2014.

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.

We did not hold any Level 3 assets or liabilities as of March 31, 2015 or December 31, 2014.

Recurring Fair Value Measurements

The following tables summarize our financial assets measured at fair value on a recurring basis as of March 31, 2015 and December 31, 2014 (in thousands):



Description	Balance as of March 31, 2015		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	76,732	$	76,732	$	—
Commercial paper	28,664		—		28,664
Short-term investments:
Commercial paper	16,774		—		16,774
Corporate bonds	144,190		—		144,190
Municipal securities	11,319		—		11,319
U.S. government agency bonds	60,358		—		60,358
U.S. government treasury bonds	17,784		17,784		—
Certificates of deposit	1,399		—		1,399
Agency discount notes	2,999		—		2,999
Long-term investments:
U.S. government agency bonds	50,587		—		50,587
Corporate bonds	66,723		—		66,723
U.S. dollar dominated foreign corporate bonds	520		—		520
U.S. government treasury bonds	33,380		33,380		—
Municipal securities	6,434		—		6,434
Asset-backed securities	10,527		—		10,527
Other assets:
Israeli funds	2,256		—		2,256
	$	530,646	$	127,896	$	402,750



Description	Balance as of December 31, 2014		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	80,786	$	80,786	$	—
Commercial paper	21,997		—		21,997
Corporate bonds	1,745		—		1,745
Short-term investments:
Commercial paper	33,998		—		33,998
Corporate bonds	151,966		—		151,966
U.S. dollar denominated foreign corporate bonds	901		—		901
Municipal securities	9,160		—		9,160
U.S. government agency bonds	41,587		—		41,587
U.S. government treasury bonds	15,777		15,777		—
Certificates of Deposits	1,398		—		1,398
Long-term investments:
U.S. government agency bonds	48,217		—		48,217
Corporate bonds	57,089		—		57,089
U.S. dollar denominated foreign corporate bonds	521		—		521
U.S. government treasury bonds	20,813		20,813		—
Municipal securities	9,551		—		9,551
Asset-backed securities	11,701		—		11,701
Other assets:
Israeli funds	2,307		—		2,307
	$	509,514	$	117,376	$	392,138

Balance Sheet Components

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

Balance Sheet Components

Inventories

Inventories consist of the following (in thousands):



	March 31, 2015		December 31, 2014
Raw materials	$	5,990	$	8,143
Work in process	4,487		2,970
Finished goods	4,095		4,815
Total Inventories	$	14,572	$	15,928

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

Accrued liabilities

Accrued liabilities consist of the following (in thousands):



	March 31, 2015		December 31, 2014
Accrued payroll and benefits	$	38,022	$	44,610
Accrued sales rebates	10,423		11,110
Accrued sales and marketing expenses	5,452		5,979
Accrued sales tax and value added tax	5,015		5,456
Accrued professional fees	4,519		2,494
Accrued income taxes	4,290		2,027
Accrued accounts payable	3,578		5,736
Accrued warranty	3,005		3,148
Other accrued liabilities	7,407		7,320
Total Accrued Liabilities	$	81,711	$	87,880

Warranty

We regularly review the accrued warranty 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 Invisalign case is complete. We accrue for warranty costs in cost of net revenues upon shipment of products. The amount of accrued estimated warranty costs is primarily based on historical experience as to product failures as well as current information on replacement costs.

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 March 31, 2015 and 2014 consists of the following activity (in thousands):



	Three Months Ended March 31,
	2015			2014
Balance at beginning of period	$	3,148		$	3,104
Charged to cost of net revenues	440			653
Actual warranty expenditures	(583		)	(709		)
Balance at end of period	$	3,005		$	3,048

Goodwill and Long-lived Assets

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

Goodwill and Long-lived Assets

Goodwill

On April 29, 2011, we acquired Cadent Holdings, Inc. (“Cadent”). In connection with the acquisition, we allocated approximately $58.0 million of goodwill to our Clear Aligner reporting unit based on the expected relative synergies generated by the acquisition. On April 30, 2013, we acquired ICA Holdings Pty Limited in a purchase business combination of which $3.6 million was recorded to goodwill, which was attributed to our Clear Aligner reporting unit.

The change in the carrying value of goodwill for the three months ended March 31, 2015, all attributable to our Clear Aligner reporting unit, is as follows (in thousands):



	Clear Aligner
Balance as of December 31, 2014	$	61,369
Adjustments ¹	(132		)
Balance as of March 31, 2015	$	61,237

¹The adjustments to goodwill during the three months ended March 31, 2015 were due to foreign currency translation.

During the fourth quarter of fiscal 2014, we performed the annual goodwill impairment testing and found no impairment events as the fair value of our Clear Aligner reporting unit was significantly in excess of the carrying value.

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



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of March 31, 2015		Accumulated Amortization			Accumulated Impairment Loss			Net Carrying Value as of March 31, 2015
Trademarks	15	$	7,100	$	(1,388	)	$	(4,179	)	$	1,533
Existing technology	13	12,600		(3,155		)	(4,328		)	5,117
Customer relationships	11	33,500		(9,562		)	(10,751		)	13,187
Other	8	285		(85		)	—			200
Total Intangible Assets		$	53,485	$	(14,190	)	$	(19,258	)	$	20,037



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2014		Accumulated Amortization			Accumulated Impairment Loss			Net Carrying Value as of December 31, 2014
Trademarks	15	$	7,100	$	(1,354	)	$	(4,179	)	$	1,567
Existing technology	13	12,600		(3,015		)	(4,328		)	5,257
Customer relationships	11	33,500		(9,095		)	(10,751		)	13,654
Other	8	285		(76		)	—			209
Total Intangible Assets		$	53,485	$	(13,540	)	$	(19,258	)	$	20,687

The total estimated annual future amortization expense for these acquired intangible assets as of March 31, 2015 is as follows (in thousands):



Fiscal Year Ending December 31,
Remainder of 2015	$	1,950
2016	2,600
2017	2,600
2018	2,600
2019	2,592
Thereafter	7,695
Total	$	20,037

Credit Facilities	3 Months Ended
Credit Facilities	Mar. 31, 2015
Notes To Financial Statements [Abstract]
Credit Facilities	Credit Facilities On March 22, 2013, we entered into a credit facility with Wells Fargo Bank. The credit facility provides for a $50.0 million revolving line of credit, with a $10.0 million letter of credit sublimit, and has a maturity date on March 22, 2016. The credit facility also requires us to maintain a minimum unrestricted cash balance of $50.0 million and comply with specific financial conditions and performance requirements. The loan bears 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 March 31, 2015, we had no outstanding borrowings under this credit facility and were in compliance with the conditions and performance requirements.

Legal Proceedings (Notes)	3 Months Ended
Legal Proceedings (Notes)	Mar. 31, 2015
Legal Proceedings [Abstract]
Legal Proceedings	Legal Proceedings Securities Class Action Lawsuit On November 28, 2012, plaintiff City of Dearborn Heights Act 345 Police & Fire Retirement System filed a lawsuit against Align, Thomas M. Prescott (“Mr. Prescott”), Align’s President and Chief Executive Officer, and Kenneth B. Arola (“Mr. Arola”), Align’s former Vice President, Finance and Chief Financial Officer, in the United States District Court for the Northern District of California on behalf of a purported class of purchasers of our common stock (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. 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. 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.

Commitments and Contingencies

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

Commitments and Contingencies

Operating Leases

As of March 31, 2015, minimum future lease payments for non-cancelable operating leases are as follows (in thousands):



Fiscal Year Ending December 31,	Operating leases
Remainder of 2015	$	7,233
2016	9,194
2017	5,463
2018	2,041
2019	188
Thereafter	188
Total minimum future lease payments	$	24,307

Off-balance Sheet Arrangements

As of March 31, 2015, 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 March 31, 2015, we did not have any material indemnification claims that were probable or reasonably possible.

Stock-based Compensation

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

Stock-based Compensation

Summary of stock-based compensation expense

As of March 31, 2015, we had a total reserve of 23,283,379 shares for issuance.

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 three months ended March 31, 2015 and 2014 is as follows (in thousands):



	Three Months Ended March 31,
	2015		2014
Cost of net revenues	$	978	$	844
Selling, general and administrative	8,771		6,717
Research and development	1,899		1,571
Total stock-based compensation	$	11,648	$	9,132

Options

Activity for the three months ended March 31, 2015 under the stock option plans is 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	Aggregate Intrinsic Value
					(in years )
Outstanding as of December 31, 2014	668		$	15.57
Granted	—		—
Exercised	(28	)	11.19
Cancelled or expired	—		—
Outstanding as of March 31, 2015	640		$	15.76	2.66	$	24,324
Vested and expected to vest at March 31, 2015	640		$	15.76	2.66	$	24,324
Exercisable at March 31, 2015	638		$	15.74	2.66	$	24,268

There were no stock options granted during the three months ended March 31, 2015 and 2014. As of March 31, 2015, the total unamortized compensation cost related to stock options is immaterial.

Restricted Stock Units (“RSU”)

A summary of the RSU activity for the three months ended March 31, 2015 is as follows (in thousands, except years):



	Number of Shares Underlying RSU		Weighted Average Grant Date Fair Value		Weighted Remaining Contractual Period	Aggregate Intrinsic Value
					(in years)
Nonvested as of December 31, 2014	2,124		$	42.08
Granted	621		56.74
Vested and released	(498	)	35.76
Forfeited	(30	)	43.30
Nonvested as of March 31, 2015	2,217		$	47.59	1.71	$	119,242

As of March 31, 2015, the total unamortized compensation cost related to RSU, net of estimated forfeitures, was $85.3 million, which we expect to recognize over a weighted average period of 2.6 years.

We have granted market-performance based restricted stock units (“MSU”) 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 MSU 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 MSU initially granted.

The following table summarizes the MSU activity for the three months ended March 31, 2015 (in thousands, except years):



	Number of Shares Underlying MSU		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Period	Aggregate Intrinsic Value
					(in years )
Nonvested as of December 31, 2014	498		$	42.00
Granted	178		56.75
Vested and released	(157	)	29.45
Nonvested as of March 31, 2015	519		$	48.08	1.81	$	27,931

As of March 31, 2015, the total unamortized compensation costs related to the MSU, net of estimated forfeitures, was $14.8 million, which we expect to recognize over a weighted average period of 1.8 years.

Employee Stock Purchase Plan ("ESPP")

In May 2010, our stockholders approved the 2010 Employee Stock Purchase Plan ("2010 Purchase Plan") which will continue until terminated by either the Board of Directors or its administrator. The maximum number of shares available for purchase under the 2010 Purchase Plan is 2,400,000 shares. As of March 31, 2015, there remains 1,226,899 shares available for purchase under the 2010 Purchase Plan.

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:



	Three Months Ended March 31,
	2015			2014
Expected term (in years)	1.2			1.2
Expected volatility	31.9		%	42.3		%
Risk-free interest rate	0.26		%	0.20		%
Expected dividends	—			—
Weighted average fair value at grant date	$	15.98		$	17.97

As of March 31, 2015, the total unamortized compensation cost related to employee purchases was $3.5 million, which we expect to recognize over a weighted average period of 0.9 year.

Common Stock Repurchase Program	3 Months Ended
Common Stock Repurchase Program	Mar. 31, 2015
Notes To Financial Statements [Abstract]
Common Stock Repurchase	Common Stock Repurchase On April 23, 2014, we announced that our Board of Directors had authorized a stock repurchase program pursuant to which we may purchase up to $300.0 million of our common stock over the next three years, with $100.0 million of that amount authorized to be purchased over the first twelve months. 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 part of our $300.0 million stock repurchase program, we entered into an accelerated share repurchase agreement ("ASR") with Goldman, Sachs & Co. on April 28, 2014 to repurchase $70.0 million of our common stock which was completed on July 2014. We received a total of approximately 1.4 million shares under the ASR for an average purchase price per share of $51.46, which all shares were retired. The final number of shares repurchased was based on our volume-weighted average stock price during the term of the transaction, less an agreed upon discount. 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 the first quarter of 2015, we repurchased on the open market approximately 0.03 million shares of our common stock at an average price of $57.49 per share, including commission for an aggregate purchase price of approximately $1.8 million. All repurchased shares were retired. In January 2015, our Board of Directors has authorized the repurchase of the next $100.0 million under the repurchase program which we anticipate completing within twelve months. As of March 31, 2015, we have $200.0 million remaining under the April 2014 stock repurchase program. On April 28, 2015, as part of our $300.0 million stock repurchase program, we entered into an ASR to repurchase $70.0 million of our common stock. Under the terms of the ASR, we paid $70.0 million on April 29, 2015 and received an initial delivery of approximately 0.8 million shares based on current market prices. The final number of shares to be repurchased will be based on our volume-weighted average stock price during the term of the transaction, less an agreed upon discount. The ASR is expected to be completed by July 29, 2015.

Accounting for Income Taxes

3 Months Ended

Mar. 31, 2015

Accounting for Income Taxes

Our provision for income taxes was $11.3 million and $10.0 million for the three months ended March 31, 2015 and 2014, respectively. This represents effective tax rates of 23.8% and 23.5%, respectively. Our effective tax rates differ from the statutory federal income tax rate of 35% due to certain foreign earnings, primarily from Costa Rica, which are subject to a lower tax rate, state income tax expense, the tax impact of certain stock-based compensation charges and unrecognized tax benefits.

We exercise significant judgment in regards to estimates of future market growth, forecasted earnings and projected taxable income in determining the provision for income taxes, and for purposes of assessing our ability to utilize any future benefit from deferred tax assets.

As of March 31, 2015, we maintained a valuation allowance of $32.7 million against deferred tax assets primarily related to Israel and California operating loss carryforwards and Australia capital loss carryforwards. These net operating and capital loss carryforwards would result in an income tax benefit if we were to conclude it is more likely than not that the related deferred tax assets will be realized.

During the three months ended March 31, 2015, the change in our gross unrecognized tax benefits was not material. The total amount of gross unrecognized tax benefits was $34.4 million as of March 31, 2015, 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. The change in accrued interest and penalties during the three months ended March 31, 2015 was not material. 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. Subsequent to March 31, 2015, we were notified by the California Franchise Tax Board that they will be examining our income tax returns for the years ended December 31, 2011 and December 31, 2012.

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 income tax incentives, which were previously granted in 2002. The incentive tax rates will expire in various years beginning in 2017. Under these incentives, all of the income in Costa Rica during these twelve year incentive periods is subject to reduced rate of Costa Rica income tax. 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 2015. As a result of these incentives, our income taxes were reduced by $8.2 million and $7.6 million for the three months ended March 31, 2015 and 2014, respectively, representing a benefit to diluted net income per share of $0.10 and $0.09 in 2015 and 2014, respectively.

Net Profit Per Share

3 Months Ended

Mar. 31, 2015

Net Profit Per Share

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 stock options, RSU, MSU and 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):



	Three Months Ended, March 31,
	2015		2014
Numerator:
Net income	$	36,177	$	32,444
Denominator:
Weighted-average common shares outstanding, basic	80,459		81,120
Dilutive effect of potential common stock	1,365		1,697
Total shares, diluted	81,824		82,817

Net income per share, basic	$	0.45	$	0.40
Net income per share, diluted	$	0.44	$	0.39

For the three months ended March 31, 2015 and 2014, the anti-dilutive effect from stock options, RSU, MSU and ESPP was not material.

Segments and Geographical Information

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

Segments and Geographical Information

Segment Information

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

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


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


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

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 Three Months Ended March 31,
Net Revenues	2015		2014
Clear Aligner	$	187,029	$	168,239
Scanner	11,057		12,407
Total net revenues	$	198,086	$	180,646

Gross profit
Clear Aligner	$	147,960	$	133,083
Scanner	3,130		4,168
Total gross profit	$	151,090	$	137,251

Geographical Information

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



	For the Three Months Ended March 31,
	2015		2014
Net revenues: ⁽¹⁾
U.S.	$	139,704	$	128,640
the Netherlands	38,645		37,391
Other international	19,737		14,615
Total net revenues	$	198,086	$	180,646

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

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



	March 31,		December 31,
	2015		2014
Long-lived assets:⁽²⁾
United States	$	80,416	$	76,511
Mexico	11,757		6,229
the Netherlands	635		874
Other International	6,956		6,511
Total long-lived assets	$	99,764	$	90,125

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

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2015
Notes To Financial Statements [Abstract]
Basis of presentation	Basis of presentation The accompanying unaudited Condensed Consolidated Financial Statements have been prepared by Align Technology, Inc. (“we”, “our”, or “Align”) in accordance with the rules and regulations of the Securities and Exchange Commission ("SEC") and contain all adjustments, including normal recurring adjustments, necessary to present fairly our results of operations for the three months ended March 31, 2015 and 2014, our comprehensive income for the three months ended March 31, 2015 and 2014, our financial position as of March 31, 2015 and our cash flows for the three months ended March 31, 2015 and 2014. The Condensed Consolidated Balance Sheet as of December 31, 2014 was derived from the December 31, 2014 audited financial statements. Net revenues by geographic area for prior period amounts in Note 13 have been reclassified to conform with the current period presentation. These reclassifications had no impact on our financial position for the three months ended March 31, 2015 and 2014. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 or any other future period, and we make no representations related thereto. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” “Quantitative and Qualitative Disclosures About Market Risk” and the Consolidated Financial Statements and notes thereto included in Items 7, 7A and 8, respectively, in our Annual Report on Form 10-K for the year ended December 31, 2014.
Use of estimates	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, useful lives of intangible assets and property and equipment, revenue recognition, stock-based compensation, 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.
Recent Accounting Pronouncements	he 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, useful lives of intangible assets and property and equipment, revenue recognition, stock-based compensation, 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. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2014-09, “Revenue from Contracts with Customers,” requiring an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The updated standard will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective and permits the use of either the retrospective or cumulative effect transition method. We expect the updated standard to become effective for us in the first quarter of fiscal 2018. We have not yet selected a transition method and we are currently evaluating the effect that the updated standard will have on our consolidated financial statements and related disclosures. In April 2015, the FASB issued ASU No. 2015-05, "Customer's Accounting for Fees Paid in a Cloud Computing Arrangement." providing guidance to entities about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the entity should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the entity should account for the arrangement as a service contract. The new guidance does not change the accounting for an entity's accounting for service contracts. The updated standard becomes effective for interim and annual reporting periods beginning after December 15, 2015. We are currently evaluating the effect that the updated standard will have on our consolidated financial statements and related disclosures.

Marketable Securities and Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

Short-Term And Long-Term Marketable Securities

As of March 31, 2015 and December 31, 2014, 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



March 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	16,774	$	—	$	—		$	16,774
Corporate bonds	144,230		31		(71		)	144,190
Municipal securities	11,310		9		—			11,319
U.S. government agency bonds	60,342		20		(4		)	60,358
U.S. government treasury bonds	17,772		12		—			17,784
Certificates of deposit	1,399		—		—			1,399
Agency discount notes	2,998		1		—			2,999
Total Marketable Securities, Short-Term	$	254,825	$	73	$	(75	)	$	254,823

Long-term



March 31, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	50,542	$	50	$	(5	)	$	50,587
Corporate bonds	66,738		30		(45		)	66,723
U.S. dollar dominated foreign corporate bonds	520		—		—			520
U.S. government treasury bonds	33,310		70		—			33,380
Municipal securities	6,425		10		(1		)	6,434
Asset-backed securities	10,533		—		(6		)	10,527
Total Marketable Securities, Long-Term	$	168,068	$	160	$	(57	)	$	168,171

Short-term



December 31, 2014	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Commercial paper	$	33,998	$	—	$	—		$	33,998
Corporate bonds	152,055		27		(116		)	151,966
U.S. dollar dominated foreign corporate bonds	901		—		—			901
Municipal securities	9,147		13		—			9,160
U.S. government agency bonds	41,574		14		(1		)	41,587
U.S. government treasury bonds	15,770		7		—			15,777
Certificates of Deposits	1,398		—		—			1,398
Total Marketable Securities, Short-Term	$	254,843	$	61	$	(117	)	$	254,787

Long-term



December 31, 2014	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government agency bonds	$	48,233	$	12	$	(28	)	$	48,217
Corporate bonds	57,195		6		(112		)	57,089
U.S. dollar dominated foreign corporate bonds	523		—		(2		)	521
U.S. government treasury bonds	20,814		5		(6		)	20,813
Municipal securities	9,552		5		(6		)	9,551
Asset-backed securities	11,713		—		(12		)	11,701
Total Marketable Securities, Long-Term	$	148,030	$	28	$	(166	)	$	147,892

Investments Classified by Contractual Maturity Date [Table Text Block]



	March 31,		December 31,
	2015		2014
Due in one year or less	$	254,823	$	254,787
Due in greater than one year	168,171		147,892
Total available for sale short-term and long-term marketable securities	$	422,994	$	402,679

Financial Assets Measured At Fair Value On Recurring Basis

The following tables summarize our financial assets measured at fair value on a recurring basis as of March 31, 2015 and December 31, 2014 (in thousands):



Description	Balance as of March 31, 2015		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	76,732	$	76,732	$	—
Commercial paper	28,664		—		28,664
Short-term investments:
Commercial paper	16,774		—		16,774
Corporate bonds	144,190		—		144,190
Municipal securities	11,319		—		11,319
U.S. government agency bonds	60,358		—		60,358
U.S. government treasury bonds	17,784		17,784		—
Certificates of deposit	1,399		—		1,399
Agency discount notes	2,999		—		2,999
Long-term investments:
U.S. government agency bonds	50,587		—		50,587
Corporate bonds	66,723		—		66,723
U.S. dollar dominated foreign corporate bonds	520		—		520
U.S. government treasury bonds	33,380		33,380		—
Municipal securities	6,434		—		6,434
Asset-backed securities	10,527		—		10,527
Other assets:
Israeli funds	2,256		—		2,256
	$	530,646	$	127,896	$	402,750



Description	Balance as of December 31, 2014		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents:
Money market funds	$	80,786	$	80,786	$	—
Commercial paper	21,997		—		21,997
Corporate bonds	1,745		—		1,745
Short-term investments:
Commercial paper	33,998		—		33,998
Corporate bonds	151,966		—		151,966
U.S. dollar denominated foreign corporate bonds	901		—		901
Municipal securities	9,160		—		9,160
U.S. government agency bonds	41,587		—		41,587
U.S. government treasury bonds	15,777		15,777		—
Certificates of Deposits	1,398		—		1,398
Long-term investments:
U.S. government agency bonds	48,217		—		48,217
Corporate bonds	57,089		—		57,089
U.S. dollar denominated foreign corporate bonds	521		—		521
U.S. government treasury bonds	20,813		20,813		—
Municipal securities	9,551		—		9,551
Asset-backed securities	11,701		—		11,701
Other assets:
Israeli funds	2,307		—		2,307
	$	509,514	$	117,376	$	392,138

Balance Sheet Components (Tables)

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

Schedule of Inventories

Inventories consist of the following (in thousands):



	March 31, 2015		December 31, 2014
Raw materials	$	5,990	$	8,143
Work in process	4,487		2,970
Finished goods	4,095		4,815
Total Inventories	$	14,572	$	15,928

Schedule of Accrued Liabilities

Accrued liabilities consist of the following (in thousands):



	March 31, 2015		December 31, 2014
Accrued payroll and benefits	$	38,022	$	44,610
Accrued sales rebates	10,423		11,110
Accrued sales and marketing expenses	5,452		5,979
Accrued sales tax and value added tax	5,015		5,456
Accrued professional fees	4,519		2,494
Accrued income taxes	4,290		2,027
Accrued accounts payable	3,578		5,736
Accrued warranty	3,005		3,148
Other accrued liabilities	7,407		7,320
Total Accrued Liabilities	$	81,711	$	87,880

Warranty Accrual

Warranty accrual as of March 31, 2015 and 2014 consists of the following activity (in thousands):



	Three Months Ended March 31,
	2015			2014
Balance at beginning of period	$	3,148		$	3,104
Charged to cost of net revenues	440			653
Actual warranty expenditures	(583		)	(709		)
Balance at end of period	$	3,005		$	3,048

Goodwill and Long-lived Assets (Tables)

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

Summary of Goodwill by Reportable Segment

The change in the carrying value of goodwill for the three months ended March 31, 2015, all attributable to our Clear Aligner reporting unit, is as follows (in thousands):



	Clear Aligner
Balance as of December 31, 2014	$	61,369
Adjustments ¹	(132		)
Balance as of March 31, 2015	$	61,237

Schedule Of Amortized Intangible Assets

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



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of March 31, 2015		Accumulated Amortization			Accumulated Impairment Loss			Net Carrying Value as of March 31, 2015
Trademarks	15	$	7,100	$	(1,388	)	$	(4,179	)	$	1,533
Existing technology	13	12,600		(3,155		)	(4,328		)	5,117
Customer relationships	11	33,500		(9,562		)	(10,751		)	13,187
Other	8	285		(85		)	—			200
Total Intangible Assets		$	53,485	$	(14,190	)	$	(19,258	)	$	20,037



	Weighted Average Amortization Period (in years)	Gross Carrying Amount as of December 31, 2014		Accumulated Amortization			Accumulated Impairment Loss			Net Carrying Value as of December 31, 2014
Trademarks	15	$	7,100	$	(1,354	)	$	(4,179	)	$	1,567
Existing technology	13	12,600		(3,015		)	(4,328		)	5,257
Customer relationships	11	33,500		(9,095		)	(10,751		)	13,654
Other	8	285		(76		)	—			209
Total Intangible Assets		$	53,485	$	(13,540	)	$	(19,258	)	$	20,687

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The total estimated annual future amortization expense for these acquired intangible assets as of March 31, 2015 is as follows (in thousands):



Fiscal Year Ending December 31,
Remainder of 2015	$	1,950
2016	2,600
2017	2,600
2018	2,600
2019	2,592
Thereafter	7,695
Total	$	20,037

Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2015

Stock-based Compensation Expense

The stock-based compensation related to all of our stock-based awards and employee stock purchases for the three months ended March 31, 2015 and 2014 is as follows (in thousands):



	Three Months Ended March 31,
	2015		2014
Cost of net revenues	$	978	$	844
Selling, general and administrative	8,771		6,717
Research and development	1,899		1,571
Total stock-based compensation	$	11,648	$	9,132

Stock Option Activity

Activity for the three months ended March 31, 2015 under the stock option plans is 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	Aggregate Intrinsic Value
					(in years )
Outstanding as of December 31, 2014	668		$	15.57
Granted	—		—
Exercised	(28	)	11.19
Cancelled or expired	—		—
Outstanding as of March 31, 2015	640		$	15.76	2.66	$	24,324
Vested and expected to vest at March 31, 2015	640		$	15.76	2.66	$	24,324
Exercisable at March 31, 2015	638		$	15.74	2.66	$	24,268

^[1]

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions

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:



	Three Months Ended March 31,
	2015			2014
Expected term (in years)	1.2			1.2
Expected volatility	31.9		%	42.3		%
Risk-free interest rate	0.26		%	0.20		%
Expected dividends	—			—
Weighted average fair value at grant date	$	15.98		$	17.97

Restricted Stock Units (RSUs)

Summary Of Nonvested Shares

A summary of the RSU activity for the three months ended March 31, 2015 is as follows (in thousands, except years):



	Number of Shares Underlying RSU		Weighted Average Grant Date Fair Value		Weighted Remaining Contractual Period	Aggregate Intrinsic Value
					(in years)
Nonvested as of December 31, 2014	2,124		$	42.08
Granted	621		56.74
Vested and released	(498	)	35.76
Forfeited	(30	)	43.30
Nonvested as of March 31, 2015	2,217		$	47.59	1.71	$	119,242

Market Performance Based Restricted Stock Units

Summary Of Nonvested Shares

The following table summarizes the MSU activity for the three months ended March 31, 2015 (in thousands, except years):



	Number of Shares Underlying MSU		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Period	Aggregate Intrinsic Value
					(in years )
Nonvested as of December 31, 2014	498		$	42.00
Granted	178		56.75
Vested and released	(157	)	29.45
Nonvested as of March 31, 2015	519		$	48.08	1.81	$	27,931

[1]	There were no stock options granted during the three months ended March 31, 2015 and 2014.

Segments and Geographical Information (Tables)

3 Months Ended

Mar. 31, 2015

Notes To Financial Statements [Abstract]

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



	For the Three Months Ended March 31,
Net Revenues	2015		2014
Clear Aligner	$	187,029	$	168,239
Scanner	11,057		12,407
Total net revenues	$	198,086	$	180,646

Gross profit
Clear Aligner	$	147,960	$	133,083
Scanner	3,130		4,168
Total gross profit	$	151,090	$	137,251

Geographical Information

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



	For the Three Months Ended March 31,
	2015		2014
Net revenues: ⁽¹⁾
U.S.	$	139,704	$	128,640
the Netherlands	38,645		37,391
Other international	19,737		14,615
Total net revenues	$	198,086	$	180,646

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

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



	March 31,		December 31,
	2015		2014
Long-lived assets:⁽²⁾
United States	$	80,416	$	76,511
Mexico	11,757		6,229
the Netherlands	635		874
Other International	6,956		6,511
Total long-lived assets	$	99,764	$	90,125

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

Short-Term and Long-Term Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Total available for sale short-term and long-term marketable securities	$ 422,994	$ 402,679
Fair Value, Measurements, Recurring [Member] \| Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	254,825	254,843
Gross Unrealized Gains	73	61
Gross Unrealized Losses	(75)	(117)
Total available for sale short-term and long-term marketable securities	254,823	254,787
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	16,774	33,998
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Total available for sale short-term and long-term marketable securities	16,774	33,998
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	144,230	152,055
Gross Unrealized Gains	31	27
Gross Unrealized Losses	(71)	(116)
Total available for sale short-term and long-term marketable securities	144,190	151,966
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| U.S. government agency bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	60,342	41,574
Gross Unrealized Gains	20	14
Gross Unrealized Losses	(4)	(1)
Total available for sale short-term and long-term marketable securities	60,358	41,587
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| US Treasury Bond Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		15,770
Gross Unrealized Gains		7
Gross Unrealized Losses		0
Total available for sale short-term and long-term marketable securities		15,777
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,398
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Total available for sale short-term and long-term marketable securities		1,398
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,310	9,147
Gross Unrealized Gains	9	13
Gross Unrealized Losses	0	0
Total available for sale short-term and long-term marketable securities	11,319	9,160
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| U.S. dollar dominated foreign corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		901
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Total available for sale short-term and long-term marketable securities		901
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| U.S. government treasury bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	17,772
Gross Unrealized Gains	12
Gross Unrealized Losses	0
Total available for sale short-term and long-term marketable securities	17,784	15,777
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,399
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Total available for sale short-term and long-term marketable securities	1,399	1,398
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Agency discount notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,998
Gross Unrealized Gains	1
Gross Unrealized Losses	0
Total available for sale short-term and long-term marketable securities	2,999
Fair Value, Measurements, Recurring [Member] \| Long-term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	168,068	148,030
Gross Unrealized Gains	160	28
Gross Unrealized Losses	(57)	(166)
Total available for sale short-term and long-term marketable securities	168,171	147,892
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	66,738	57,195
Gross Unrealized Gains	30	6
Gross Unrealized Losses	(45)	(112)
Total available for sale short-term and long-term marketable securities	66,723	57,089
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| Foreign Government Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	520
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Total available for sale short-term and long-term marketable securities	520	521
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| U.S. government agency bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	50,542	48,233
Gross Unrealized Gains	50	12
Gross Unrealized Losses	(5)	(28)
Total available for sale short-term and long-term marketable securities	50,587	48,217
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,533	11,713
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(6)	(12)
Total available for sale short-term and long-term marketable securities	10,527	11,701
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,425	9,552
Gross Unrealized Gains	10	5
Gross Unrealized Losses	(1)	(6)
Total available for sale short-term and long-term marketable securities	6,434	9,551
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| U.S. dollar dominated foreign corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		523
Gross Unrealized Gains		0
Gross Unrealized Losses		(2)
Total available for sale short-term and long-term marketable securities	520	521
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| U.S. government treasury bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	33,310	20,814
Gross Unrealized Gains	70	5
Gross Unrealized Losses	0	(6)
Total available for sale short-term and long-term marketable securities	$ 33,380	$ 20,813

Marketable Securities and Fair Value Measurements Available For Sale Securities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Due in one year or less	$ 254,823	$ 254,787
Due in greater than one year	168,171	147,892
Total available for sale short-term and long-term marketable securities	$ 422,994	$ 402,679

Summary of Financial Assets Measured at Fair Value on Recurring Basis (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	$ 422,994,000	$ 402,679,000
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	530,646,000	509,514,000
Fair Value, Measurements, Recurring [Member] \| Israeli Severance Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other assets	2,256,000	2,307,000
Fair Value, Measurements, Recurring [Member] \| Cash Equivalents \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents	76,732,000	80,786,000
Fair Value, Measurements, Recurring [Member] \| Cash Equivalents \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents	28,664,000	21,997,000
Fair Value, Measurements, Recurring [Member] \| Cash Equivalents \| U.S. dollar dominated foreign corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents		1,745,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	254,823,000	254,787,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	16,774,000	33,998,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	144,190,000	151,966,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| U.S. dollar dominated foreign corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments		901,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| U.S. government agency bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	60,358,000	41,587,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| U.S. government treasury bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	17,784,000	15,777,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Agency discount notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	2,999,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	1,399,000	1,398,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	11,319,000	9,160,000
Fair Value, Measurements, Recurring [Member] \| Short-term Investments \| Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments		1,398,000
Fair Value, Measurements, Recurring [Member] \| Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	168,171,000	147,892,000
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	66,723,000	57,089,000
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| U.S. dollar dominated foreign corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	520,000	521,000
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| U.S. government agency bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	50,587,000	48,217,000
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| Foreign bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	520,000	521,000
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| U.S. government treasury bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	33,380,000	20,813,000
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	6,434,000	9,551,000
Fair Value, Measurements, Recurring [Member] \| Long-term Investments \| Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	10,527,000	11,701,000
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	127,896,000	117,376,000
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Israeli Severance Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other assets	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Cash Equivalents \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents	76,732,000	80,786,000
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Cash Equivalents \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Cash Equivalents \| U.S. dollar dominated foreign corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents		0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments \| U.S. dollar dominated foreign corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments		0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments \| U.S. government agency bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments \| U.S. government treasury bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	17,784,000	15,777,000
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments \| Agency discount notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Short-term Investments \| Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long-term Investments \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long-term Investments \| U.S. dollar dominated foreign corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long-term Investments \| U.S. government agency bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long-term Investments \| Foreign bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments		0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long-term Investments \| U.S. government treasury bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	33,380,000	20,813,000
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long-term Investments \| Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Long-term Investments \| Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, Fair Value Disclosure	402,750,000	392,138,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Israeli Severance Funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other assets	2,256,000	2,307,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Cash Equivalents \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents	0	0
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Cash Equivalents \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents	28,664,000	21,997,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Cash Equivalents \| U.S. dollar dominated foreign corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash equivalents		1,745,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Short-term Investments \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	16,774,000	33,998,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Short-term Investments \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	144,190,000	151,966,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Short-term Investments \| U.S. dollar dominated foreign corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments		901,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Short-term Investments \| U.S. government agency bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	60,358,000	41,587,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Short-term Investments \| U.S. government treasury bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Short-term Investments \| Agency discount notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	2,999,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Short-term Investments \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	1,399,000	1,398,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Short-term Investments \| Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	11,319,000	9,160,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Long-term Investments \| Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	66,723,000	57,089,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Long-term Investments \| U.S. dollar dominated foreign corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	520,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Long-term Investments \| U.S. government agency bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	50,587,000	48,217,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Long-term Investments \| Foreign bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments		521,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Long-term Investments \| U.S. government treasury bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Long-term Investments \| Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	6,434,000	9,551,000
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) \| Long-term Investments \| Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	$ 10,527,000	$ 11,701,000

Inventories (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Disclosure Inventories [Abstract]
Raw materials	$ 5,990	$ 8,143
Work in process	4,487	2,970
Finished goods	4,095	4,815
Total Inventories	$ 14,572	$ 15,928

Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Disclosure Accrued Liabilities [Abstract]
Accrued payroll and benefits	$ 38,022	$ 44,610
Accrued sales rebate	10,423	11,110
Accrued sales tax and value added tax	5,015	5,456
Accrued sales and marketing expenses	5,452	5,979
Accrued accounts payable	3,578	5,736
Accrued warranty	3,005	3,148
Accrued professional fees	4,519	2,494
Accrued income taxes	4,290	2,027
Other accrued liabilities	7,407	7,320
Total Accrued Liabilities	$ 81,711	$ 87,880

Warranty Accrual Activity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 3,148	$ 3,104
Charged to cost of revenues	440	653
Actual warranty expenditures	(583)	(709)
Balance at end of period	$ 3,005	$ 3,048

Change in Carrying Value of Goodwill (Details) (USD $)
In Thousands, unless otherwise specified

3 Months Ended

Mar. 31, 2015

Dec. 31, 2014

Mar. 31, 2015

Clear Aligner [Member]

Goodwill [Roll Forward]

Balance as of December 31, 2014

$ 81,274

$ 82,056

$ 61,369

Adjustments

(132)

^[1]

Balance as of March 31, 2015

$ 81,274

$ 82,056

$ 61,237

[1]	The adjustments to goodwill during the three months ended March 31, 2015 were due to foreign currency translation.

Intangible Assets as Direct Result from Cadent Acquisition (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2013	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, beginning balance	$ 53,485		$ 53,485
Accumulated Amortization	(14,190)		(13,540)
Accumulated Impairment Loss	(19,258)		(19,258)
Net Carrying Value, ending balance	20,037		20,687
Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	15 years	15 years
Gross Carrying Amount, beginning balance	7,100		7,100
Accumulated Amortization	(1,388)		(1,354)
Accumulated Impairment Loss	(4,179)		(4,179)
Net Carrying Value, ending balance	1,533		1,567
Existing technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	13 years	13 years
Gross Carrying Amount, beginning balance	12,600		12,600
Accumulated Amortization	(3,155)		(3,015)
Accumulated Impairment Loss	(4,328)		(4,328)
Net Carrying Value, ending balance	5,117		5,257
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	11 years	11 years
Gross Carrying Amount, beginning balance	33,500		33,500
Accumulated Amortization	(9,562)		(9,095)
Accumulated Impairment Loss	(10,751)		(10,751)
Net Carrying Value, ending balance	13,187		13,654
Other
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	8 years	8 years
Gross Carrying Amount, beginning balance	285		285
Accumulated Amortization	(85)		(76)
Accumulated Impairment Loss	0		0
Net Carrying Value, ending balance	$ 200		$ 209

Total Estimated Annual Future Amortization Expense for Acquired Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Disclosure Total Estimated Annual Future Amortization Expense For Acquired Intangible Assets [Abstract]
Remainder of 2015	$ 1,950
2015	2,600
2016	2,600
2017	2,600
2018	2,592
Thereafter	7,695
Net Carrying Value, ending balance	$ 20,037	$ 20,687

Credit Facilities - Additional Information (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended
	Mar. 22, 2013	Mar. 31, 2015 Revolving Credit Facility [Member] Wells Fargo [Member]	Mar. 22, 2013 Revolving Credit Facility [Member] Wells Fargo [Member]	Mar. 31, 2015 Letter of Credit [Member] Wells Fargo [Member]	Mar. 22, 2013 Letter of Credit [Member] Wells Fargo [Member]
Line of Credit Facility [Line Items]
Line of credit, available borrowings			$ 50.0		$ 10.0
Unrestricted Cash Deposit		50.0
Debt Instrument, Basis Spread on Variable Rate	1.75%
Line of Credit Facility, Amount Outstanding				$ 0

Minimum Future Lease Payments for Non-Cancelable Leases (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015
Disclosure Minimum Future Lease Payments For Non Cancelable Leases [Abstract]
Remainder of 2015	$ 7,233
2015	9,194
2016	5,463
2017	2,041
2018	188
Thereafter	188
Total minimum lease payments	$ 24,307

Stock-based Compensation - Additional Information (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Incentive Plan 2005
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance	23,283,379
Employee Stock Purchase Plan 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available	2,400,000
Number of shares remaining	1,226,899
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unamortized compensation cost	$ 85.3
Weighted average period of total unamortized cost (in years)	2 years 7 months
Market Performance Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unamortized compensation cost	14.8
Weighted average period of total unamortized cost (in years)	1 year 9 months 6 days
Market Performance Based Restricted Stock Units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of granted market-performance based restricted stock units	2 years
Market Performance Based Restricted Stock Units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of granted market-performance based restricted stock units	3 years
Percentage of market-performance based restricted stock units eligible to vest over the vesting period	150.00%
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unamortized compensation cost	$ 3.5
Weighted average period of total unamortized cost (in years)	11 months 6 days

Stock-Based Compensation Expense Related to All Stock-Based Awards and Employee Stock Purchases (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 11,648	$ 9,132
Cost of net revenues
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	978	844
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	8,771	6,717
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,899	$ 1,571

Activity Under Stock Option Plans (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Number of Shares Underlying Stock Options
Outstanding as of December 31, 2014	668
Granted	0
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 0
Exercised	(28)
Cancelled or expired	0
Outstanding as of March 31, 2015	640
Vested and expected to vest at March 31, 2015	640
Exercisable at March 31, 2015	638
Weighted Average Exercise Price per Share
Outstanding as of December 31, 2014	$ 15.57
Exercised	$ 11.19
Cancelled or expired	$ 0.00
Outstanding as of March 31, 2015	$ 15.76
Vested and expected to vest at June 30, 2014 (usd per share)	$ 15.76
Exercisable at June 30, 2014 (usd per share)	$ 15.74
Weighted Average Remaining Contractual Term
Outstanding as of March 31, 2015	2 years 7 months 28 days
Vested and expected to vest at March 31, 2015	2 years 7 months 28 days
Exercisable at March 31, 2015	2 years 7 months 28 days
Aggregate Intrinsic Value
Outstanding as of March 31, 2015	$ 24,324
Vested and expected to vest at March 31, 2015	24,324
Exercisable at March 31, 2015	$ 24,268

Summary of Nonvested Shares (Details) (Restricted Stock Units (RSUs), USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Restricted Stock Units (RSUs)
Number of Shares Underlying RSUs
Nonvested as of December 31, 2014	2,124
Granted	621
Vested and released	(498)
Forfeited	(30)
Nonvested as of March 31, 2015	2,217
Weighted Average Grant Date Fair Value
Nonvested as of December 31, 2014	$ 42,000
Granted	$ 57,000
Vested and released	$ 36,000
Forfeited	$ 43,000
Nonvested as of March 31, 2015	$ 47,590
Weighted Remaining Vesting Period
Nonvested as of March 31, 2015	1 year 8 months 16 days
Aggregate Intrinsic Value
Nonvested as of March 31, 2015	$ 119,242

Summary of MSU Performance (Details) (Market Performance Based Restricted Stock Units, USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Market Performance Based Restricted Stock Units
Number of Shares Underlying MSUs
Nonvested as of December 31, 2014	498
Granted	178
Vested and released	(157)
Nonvested as of March 31, 2015	519
Weighted Average Grant Date Fair Value
Nonvested as of December 31, 2014	$ 42,000
Granted	$ 57,000
Vested and released	$ 29,000
Nonvested as of March 31, 2015	$ 48,080
Weighted Average Remaining Vesting Period
Nonvested as of March 31, 2015	1 year 9 months 22 days
Aggregate Intrinsic Value
Nonvested as of March 31, 2015	$ 27,931

Stock-based Compensation Stock-based Compensation Employee Stock Purchase Plan (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected term (in years)	1 year 2 months 12 days	1 year 2 months 12 days
Expected volatility	31.90%	42.30%
Risk-free interest rate	0.26%	0.20%
Expected dividends	0.00%	0.00%
Weighted average fair value at grant date (USD per Share)	$ 15.98	$ 17.97

Common Stock Repurchase Program - Additional Information (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended		3 Months Ended	12 Months Ended		0 Months Ended
	Apr. 28, 2014	Apr. 23, 2014	Mar. 31, 2015	Dec. 31, 2014	Jan. 31, 2015	Jul. 29, 2014 Accelerated Share Repurchase Program [Member]	Apr. 28, 2015 Subsequent Event	Apr. 28, 2015 Subsequent Event
Share Repurchases [Line Items]
Repurchase of common stock, common stock authorized		$ 300.0			$ 100.0
Stock repurchase program, authorized amount for next twelve months		100.0
Accelerated share repurchase, contracted amount of repurchase	70.0						70.0
Payments under accelerated share repurchase agreement								70.0
Treasury Stock, Shares, Acquired						1.4	0.8
Share Repurchases Price Paid Per Share						$ 51.46
Stock Repurchased During Period, Shares			0.03	0.60
Stock Repurchased During Period, Average Price Per Share			$ 57.49	$ 50.93
Stock Repurchased During Period, Value			1.8	28.2
Stock Repurchase Program, Remaining Authorized Repurchase Amount			$ 200.0

Accounting for Income Taxes - Additional Information (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Taxes [Line Items]
Provision for income taxes	$ 11,295,000	$ 9,961,000
Effective income tax rate, continuing operations	23.80%	23.50%
Statutory rate	35.00%
Valuation allowance, deferred tax asset	32,700,000
Unrecognized tax benefits	34,400,000
Tax holiday effect on diluted earnings per share	$ 0.10	$ 0.09
Foreign Tax Authority [Member]
Income Taxes [Line Items]
Foreign income tax rate	30.00%
Tax Holiday effect	$ 8,200,000	$ 7,600,000

Computation of Basic and Diluted Net Profit Per Share Attributable to Common Stock (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Disclosure Computation Of Basic And Diluted Net Profit Per Share Attributable To Common Stock [Abstract]
Net income	$ 36,177	$ 32,444
Weighted-average common shares outstanding, basic	80,459	81,120
Dilutive effect of potential common stock	1,365	1,697
Total shares, diluted	81,824	82,817
Net income per share, basic	$ 0.45	$ 0.40
Net income per share, diluted	$ 0.44	$ 0.39