ZELTIQ Aesthetics (ZLTQ) 10-Q 28 Oct 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 22, 2015
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Entity Registrant Name	Zeltiq Aesthetics Inc
Entity Central Index Key	1,415,336
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		39,025,926

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
CURRENT ASSETS:
Cash and cash equivalents	$ 35,618	$ 28,649
Short-term investments	11,235	16,286
Accounts receivable, net	32,908	21,472
Inventory	28,783	15,536
Prepaid expenses and other current assets	8,716	7,060
Total current assets	117,260	89,003
Long-term investments	3,620	4,805
Restricted cash	459	560
Property and equipment, net	4,770	3,724
Intangible asset, net	5,255	5,780
Other assets	147	33
Total assets	131,511	103,905
CURRENT LIABILITIES:
Accounts payable	12,159	5,824
Accrued and other current liabilities	32,019	21,450
Deferred revenue	7,198	5,069
Current portion of capital lease obligations	123	120
Total current liabilities	51,499	32,463
Long-term deferred revenue	157	622
Long-term capital lease obligations, less current portion	170	262
Other non-current liabilities	568	39
Total liabilities	$ 52,394	$ 33,386
Commitments and contingencies
STOCKHOLDERS’ EQUITY:
Preferred stock, $0.01 par value: 50,000,000 shares authorized and no shares issued and outstanding at September 30, 2015 and December 31, 2014	$ 0	$ 0
Common stock, $0.001 par value: 500,000,000 shares authorized at September 30, 2015, and December 31, 2014; 39,002,669 and 38,123,998 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	42	42
Additional paid-in capital	210,547	202,701
Accumulated other comprehensive loss	(1,140)	(696)
Accumulated deficit	(130,332)	(131,528)
Total stockholders’ equity	79,117	70,519
Total liabilities and stockholders’ equity	$ 131,511	$ 103,905

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	39,002,669	38,123,998
Common stock, shares outstanding	39,002,669	38,123,998

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Revenue	$ 61,202	$ 45,670	$ 177,191	$ 123,706
Cost of revenue	16,041	12,555	48,535	35,231
Gross profit	45,161	33,115	128,656	88,475
Operating expenses:
Research and development	5,464	4,241	17,352	12,861
Sales and marketing	30,647	19,014	87,253	60,253
General and administrative	7,115	4,896	22,156	14,843
Total operating expenses	43,226	28,151	126,761	87,957
Income from operations	1,935	4,964	1,895	518
Interest income, net	13	14	40	47
Other income (expense), net	359	(189)	(508)	(338)
Income before income taxes	2,307	4,789	1,427	227
Provision for income taxes	160	7	231	13
Net income	$ 2,147	$ 4,782	$ 1,196	$ 214
Basic net income per share:
Net income per share, basic (dollars per share)	$ 0.06	$ 0.13	$ 0.03	$ 0.01
Weighted average shares of common stock outstanding used in computing net income per share, basic (shares)	38,881,183	37,630,222	38,640,269	37,430,337
Diluted net income per share:
Net income per share, diluted (dollars per share)	$ 0.05	$ 0.12	$ 0.03	$ 0.01
Weighted average shares of common stock outstanding used in computing net income per share, diluted (shares)	40,860,593	40,926,034	40,724,261	40,781,141

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 2,147	$ 4,782	$ 1,196	$ 214
Other comprehensive loss, net of tax:
Foreign currency translation adjustments	(661)	(450)	(451)	(271)
Changes in unrealized gains (losses) on available-for-sale securities	2	(2)	7	(6)
Other comprehensive loss, net of tax	(659)	(452)	(444)	(277)
Comprehensive income (loss)	$ 1,488	$ 4,330	$ 752	$ (63)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 1,196	$ 214
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	1,712	1,350
Stock-based compensation	10,261	7,029
Deferred income taxes	0	37
Amortization of investment premium, net	63	183
Provision for doubtful accounts receivable	270	134
Provision for excess and obsolete inventory	403	688
Loss on disposal and write-off of property and equipment	0	17
Changes in operating assets and liabilities:
Accounts receivable	(11,773)	(5,653)
Inventory	(13,698)	(9,684)
Prepaid expenses and other assets	(1,794)	177
Deferred revenue, net of deferred costs	1,681	2,426
Accounts payable, accrued and other liabilities	17,573	(2,076)
Net cash provided by (used in) operating activities	5,894	(5,158)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of investments	(12,079)	(9,011)
Proceeds from sale of investments	0	1,000
Proceeds from maturity of investments	18,260	14,968
Purchase of property and equipment	(2,332)	(1,216)
Change in restricted cash	94	(252)
Net cash provided by investing activities	3,943	5,489
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments on capital leases	(89)	0
Proceeds from issuance of common stock upon exercise of stock options and from employee stock purchase program	4,136	2,714
Tax payments related to shares withheld for vested restricted stock units	(6,577)	(3,774)
Tax effect of employee stock plans	26	27
Net cash used in financing activities	(2,504)	(1,033)
Effect of exchange rate changes on cash and cash equivalents	(364)	(155)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	6,969	(857)
CASH AND CASH EQUIVALENTS—Beginning of period	28,649	25,798
CASH AND CASH EQUIVALENTS—End of period	$ 35,618	$ 24,941

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation The accompanying interim condensed consolidated financial statements of ZELTIQ Aesthetics, Inc. (the "Company") are unaudited. These interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP, and the applicable rules and regulations of the Securities and Exchange Commission, or SEC, for interim financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. The December 31, 2014 condensed consolidated balance sheet was derived from the audited financial statements as of that date, but does not include all of the information and footnotes required by GAAP for complete financial statements. The accompanying unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments of a normal recurring nature considered necessary to state fairly the Company's financial position as of September 30, 2015 , results of operations for the three and nine months ended September 30, 2015 and 2014 , comprehensive income (loss) for the three and nine months ended September 30, 2015 and 2014 , and cash flows for the nine months ended September 30, 2015 and 2014 . The interim results for the three and nine months ended September 30, 2015 , are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 , or for any other future annual or interim period. Certain amounts in the prior year's condensed consolidated balance sheet have been reclassified to conform to the current period's presentation. These reclassifications had no impact on previously reported condensed consolidated statements of cash flows or statements of operations. 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 the Company's Annual Report on Form 10-K for the year ended December 31, 2014 . Out of period adjustment During the three months ended June 30, 2015, the Company recorded an out-of-period adjustment of $0.2 million to increase cost of revenue to write-off of certain inventory held by vendors. Of this adjustment, $0.1 million , $23,000 and $42,000 related to the fiscal years ended December 31, 2012 , 2013 and 2014 , respectively. The Company does not believe that such amounts are material to any prior period consolidated financial statements, and the impact of correcting these errors in the nine months ended September 30, 2015 is not material to the current consolidated financial statements. Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated. The functional currency of the Company’s international subsidiaries is evaluated on a case-by-case basis and has been determined to be the respective local currency. All assets and liabilities of these foreign operations are translated to U.S. Dollars at current period end exchange rates, and revenue and expenses are translated to U.S. Dollars using average exchange rates in effect during the period. The gains and losses from the foreign currency translation of the foreign subsidiaries' financial statements are included as a separate component of stockholders' equity under "Accumulated other comprehensive income (loss)." Gains or losses arising from currency exchange rate fluctuations on transactions denominated in a currency other than the local functional currency are included in other income (expense), net. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reported periods. The primary estimates underlying the Company's financial statements include the value of revenue elements, product warranty, inventory valuation, allowance for doubtful accounts receivable, assumptions regarding variables used in calculating the fair value of the Company's equity awards, fair value of investments, useful lives of intangibles, income taxes and contingent liabilities. Actual results could differ from those estimates. Concentration of Credit Risk As of September 30, 2015 and December 31, 2014 , one individual customer, which is a large aesthetic chain, accounted for 27% and 24% of accounts receivable, respectively. During the three months ended September 30, 2015 , no individual customer accounted for 10% or more of total revenue. During the nine months ended September 30, 2015 , one individual customer accounted for 12% of total revenue. During the three and nine months ended September 30, 2014 , no individual customer accounted for 10% or more of total revenue. Critical Accounting Policies There have been no changes to the Company’s critical accounting policies during the nine months ended September 30, 2015 , as compared to the critical accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 . Recent Accounting Pronouncements On May 28, 2014 , the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers. The objective of this update is to provide a single, comprehensive revenue recognition model for all contracts with customers to improve comparability within industries, across industries, and across capital markets. This standard update contains principles that the Company will apply to determine the measurement of revenue and timing of when it is recognized. This guidance allows for two methods of adoption: (a) full retrospective adoption, meaning the guidance is applied to all periods presented, or (b) modified retrospective adoption, meaning the cumulative effect of applying this guidance is recognized as an adjustment to the fiscal 2018 opening Accumulated deficit balance. The Company expects to adopt this guidance effective January 1, 2018 , and is currently evaluating the two adoption methods as well as the impact this new guidance will have on its consolidated financial statements and related disclosures. In August 2014 , the FASB issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties About an Entity's Ability to Continue as a Going Concern. This standard update provides guidance around management's responsibility to evaluate whether there is substantial doubt about an entity's ability to continue as a going concern and to provide related footnote disclosures. The new guidance is effective for all annual and interim periods ending after December 15, 2016 . The new guidance is not expected to have an impact on the Company's consolidated financial statements and related disclosures. In April 2015 , the FASB issued Accounting Standards Update No. 2015-05 regarding Subtopic 350-40, “Intangibles - Goodwill and Other - Internal-Use Software.” This standard provides guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The amendments are effective for annual and interim periods beginning after December 15, 2015 . Early adoption is permitted. The amendments may be applied either prospectively to all arrangements entered into or materially modified after the effective date or retrospectively. The Company is currently evaluating the impact this new guidance will have on its consolidated financial statements and related disclosures. In June 2015 , the FASB issued Accounting Standards Update No. 2015-10, Technical Corrections and Improvements. The standard covers a wide range of Topics in the Codification. The amendments in this standard represent changes to clarify the Codification, correct unintended application of guidance, or make minor improvements to the Codification that are not expected to have a significant effect on current accounting practice or create a significant administrative cost on most entities. The amendments are effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2015 . The Company does not anticipate that the adoption of this standard will have a material impact on its consolidated financial statements and footnote disclosures. The Company is currently evaluating the impact this new guidance will have on its consolidated financial statements and related disclosures. In July 2015 , the FASB amended ASC Topic 330, Inventory ("ASC 330") to simplify the measurement of inventory. The amendments require that an entity measure inventory at the lower of cost and net realizable value instead of the lower of cost and market. This guidance is effective for public companies for years, and interim periods within those years, beginning on or after December 15, 2016, with earlier application permitted as of the beginning of an interim or annual reporting period. This guidance will be effective for the Company beginning in its first quarter of fiscal 2017. The Company is currently evaluating the impact this new guidance will have on its consolidated financial statements and related disclosures.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices 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 assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The categorization of a financial instrument within the valuation hierarchy is based on the lowest level of input that is significant to the fair value measurement. The Company classifies its cash equivalents and investments within Level 1 and Level 2, as it uses quoted market prices or alternative pricing sources and models utilizing market observable inputs. The following tables set forth the fair value of the Company’s financial assets and liabilities by level within the fair value hierarchy (in thousands): As of September 30, 2015 Level 1 Level 2 Level 3 Fair Value Financial Assets Cash equivalents: Money market funds $ 6,371 $ — $ — $ 6,371 Commercial paper — 500 — 500 Short-term investments: U.S. Agency securities — 1,651 — 1,651 U.S. Treasury — 500 — 500 Corporate bonds — 6,869 — 6,869 Commercial paper — 500 — 500 Certificates of deposit 1,715 — — 1,715 Long-term investments: U.S. Agency securities — 250 — 250 Corporate bonds — 611 — 611 Certificates of deposit 2,759 — — 2,759 Total $ 10,845 $ 10,881 $ — $ 21,726 As of December 31, 2014 Level 1 Level 2 Level 3 Fair Value Financial Assets Cash equivalents: Money market funds $ 6,062 $ — $ — $ 6,062 Short-term investments: U.S. Agency securities — 5,240 — 5,240 U.S. Treasury — 1,004 — 1,004 Corporate bonds — 7,774 — 7,774 Commercial paper — 1,349 — 1,349 Certificates of deposit 919 — — 919 Long-term investments: U.S. Agency securities — 999 — 999 U.S. Treasury — 500 — 500 Corporate bonds — 750 — 750 Certificates of deposit 2,556 — — 2,556 Total $ 9,537 $ 17,616 $ — $ 27,153 During the three and nine months ended September 30, 2015 and 2014 , the Company did not have any transfers of financial assets measured at fair value on a recurring basis to or from Level 1, Level 2 or Level 3. The Company did not hold any Level 3 assets or liabilities as of September 30, 2015 , and December 31, 2014 . The carrying amounts of the Company’s cash equivalents, accounts receivable and accounts payable approximate fair value due to their relatively short maturities.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Investments The Company's short-term and long-term investments as of September 30, 2015 are as follows (in thousands): Short-term Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Agency securities $ 1,651 $ — $ — $ 1,651 U.S. Treasury 500 — — 500 Corporate bonds 6,868 2 (1 ) 6,869 Commercial paper 500 — — 500 Certificates of deposit 1,715 — — 1,715 Total $ 11,234 $ 2 $ (1 ) $ 11,235 Long-term Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Agency securities $ 250 $ — $ — $ 250 Corporate bonds 612 — (1 ) 611 Certificates of deposit 2,759 — — 2,759 Total $ 3,621 $ — $ (1 ) $ 3,620 The Company's short-term and long-term investments as of December 31, 2014 are as follows (in thousands): Short-term Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Agency securities $ 5,240 $ 1 $ (1 ) $ 5,240 U.S. Treasury 1,003 1 — 1,004 Corporate bonds 7,778 2 (6 ) 7,774 Commercial paper 1,349 — — 1,349 Certificates of deposit 919 — — 919 Total $ 16,289 $ 4 $ (7 ) $ 16,286 Long-term Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Agency securities $ 1,000 $ — $ (1 ) $ 999 U.S. Treasury 500 — — 500 Corporate bonds 752 — (2 ) 750 Certificates of deposit 2,556 — — 2,556 Total $ 4,808 $ — $ (3 ) $ 4,805 For each of the three and nine months ended September 30, 2015 and 2014 , gains or losses realized on the sale of investments were insignificant. The contractual maturities of the Company's short-term and long-term investments as of September 30, 2015 , are as follows (in thousands): September 30, 2015 Amortized Cost Fair Value Due in one year or less $ 11,234 $ 11,235 Due in one year to five years 3,621 3,620 $ 14,855 $ 14,855 When evaluating the investments for other-than-temporary impairment, the Company reviews factors such as the length of time and extent to which fair value has been below the amortized cost basis, review of current market liquidity, interest rate risk, the financial condition of the issuer, as well as credit rating downgrades. The Company believes that the unrealized losses are not other-than-temporary. The Company does not have a foreseeable need to liquidate the portfolio and anticipates recovering the full cost of the securities either as market conditions improve, or as the securities mature. Inventory Inventory is stated at the lower of cost (which approximates actual cost on a first-in, first-out basis) or market. Inventory that is obsolete or in excess of forecasted usage is written down to its estimated net realizable value based on assumptions about future demand, new production introductions and market conditions. The components of inventory consist of the following (in thousands): September 30, December 31, Raw materials $ 10,354 $ 7,692 Finished goods 18,429 7,844 Total inventory $ 28,783 $ 15,536 Property and equipment, net Property and equipment, net comprised the following (in thousands): September 30, December 31, Lab equipment, tooling and molds $ 3,221 $ 2,766 Computer software 2,072 1,337 Computer equipment 1,443 984 Leasehold improvements 1,708 1,452 Furniture and fixtures 924 494 Vehicles 51 35 Total property and equipment 9,419 7,068 Less: Accumulated depreciation and amortization (5,224 ) (4,111 ) Construction in progress 575 767 Property and equipment, net $ 4,770 $ 3,724 The table above includes property and equipment acquired under capital leases which totaled $0.4 million as of both September 30, 2015 and December 31, 2014 . Depreciation and amortization expense related to property and equipment was $0.5 million and $1.2 million for the three and nine months ended September 30, 2015 , respectively. Depreciation and amortization expense related to property and equipment was $0.2 million and $0.8 million for the three and nine months ended September 30, 2014 , respectively. Accrued and Other Current Liabilities The following table shows the components of accrued liabilities (in thousands): September 30, December 31, Accrued payroll and employee related expenses $ 11,930 $ 8,386 Accrued marketing expenses 5,031 2,959 Accrued royalty 4,142 3,612 Sales and other taxes payable 2,929 2,123 Advance payments from customers 4,200 1,908 Accrued warranty 536 569 Accrued legal expenses 2,114 592 Other 1,137 1,301 Total accrued and other current liabilities $ 32,019 $ 21,450 Product Warranty The Company provides a standard limited warranty on its products of generally one year for both control units and applicators for its direct customers. For indirect customers in international markets, the Company provides a standard limited warranty on its products of generally three years for control units and one year for applicators. The Company accrues for the estimated future costs of repair or replacement upon shipment. Changes in the warranty accrual are recorded to cost of revenue and is based upon historical and forecasted trends in the volume of product failures during the warranty period and the cost to repair or replace the equipment. The Company bases product warranty costs on related freight, material, technical support labor and overhead costs. The estimated product warranty costs are assessed by considering historical costs and applying the experienced failure rates to the outstanding warranty period for products sold. The Company exercises judgment in estimating the expected product warranty costs, using data such as the actual and projected product failure rates, and average repair costs, including freight, material, technical support labor, and overhead costs, for products returned under warranty. The product warranty accrual was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Balance at the beginning of the period $ 339 $ 741 $ 569 $ 676 Warranty costs incurred (377 ) (170 ) (721 ) (643 ) Net changes in liability for pre-existing warranties, including expirations 516 18 520 423 Provision for warranty 58 112 168 245 Balance at the end of the period $ 536 $ 701 $ 536 $ 701

Intangible Asset, Net

Intangible Asset, Net	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Asset, Net	Intangible Asset, Net The Company's intangible asset consists of an exclusive license agreement with Massachusetts General Hospital, or MGH, for commercializing patents and other technology. All milestone payments payable by the Company pursuant to the terms of the agreement subsequent to the date of the Food and Drug Administration, or FDA, clearance were capitalized as purchased technology when paid, and are subsequently amortized into cost of revenue using the straight-line method over the estimated remaining useful life of the technology, not to exceed the term of the agreement or the life of the patent. Intangible asset, net comprised the following (in thousands): September 30, December 31, Purchased technology $ 8,050 $ 8,050 Less: Accumulated amortization (2,795 ) (2,270 ) Intangible asset, net $ 5,255 $ 5,780 Amortization expense of the intangible asset was $0.2 million for both the three months ended September 30, 2015 and 2014 , and $0.5 million for both the nine months ended September 30, 2015 and 2014 . The total estimated annual future amortization expense of this intangible asset as of September 30, 2015 , is as follows (in thousands): Fiscal Year 2015 (remaining 3 months) $ 176 2016 701 2017 701 2018 701 2019 701 Thereafter 2,275 Total $ 5,255

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Brazilian Distribution Agreement The Company entered into a distribution agreement with ADVANCE Medical, Inc. and its wholly-owned subsidiaries, or ADVANCE, dated March 18, 2011 , as the Company's exclusive distributor of CoolSculpting in Brazil and Mexico, as amended on August 29, 2011 , February 27, 2012 and September 4, 2012 . The distribution agreement was further amended on August 15, 2014 , whereby ADVANCE is no longer a distributor in Mexico, effective November 13, 2014 . As the exclusive distributor in Brazil, ADVANCE is required to purchase a minimum quantity of the Company’s products each calendar quarter throughout the term of the distribution agreement which expires on December 31, 2018 . Venrock, a principal stockholder of the Company, owns an equity interest in ADVANCE Medical, Ltd., the parent company of ADVANCE. Dr. Bryan E. Roberts, who is a member of the Company's Board of Directors, is also a partner of Venrock Associates. ADVANCE purchases product with payment terms up to 180 days , and to date no amounts have been determined to be unrecoverable. The revenue recognized by the Company under this distribution agreement was $1.4 million and $2.9 million for the three and nine months ended September 30, 2015 , respectively, compared to $0.2 million and $1.3 million for the three and nine months ended September 30, 2014 , respectively. The accounts receivable balance under this distribution agreement was $1.7 million and $0.2 million as of September 30, 2015 and December 31, 2014 , respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Lease Obligations The Company leases facilities under non-cancellable operating leases with various expiration dates. Specifically, the Company occupies a facility in Pleasanton, California, under a lease which extends through March 2019 , a manufacturing facility in Dublin, California, under a lease which extends through May 2017 , and a warehouse space in Livermore, California, under a lease which extends through May 2017 . The Company also occupies office and warehouse space near Gatwick, United Kingdom, under a lease which extends through December 2018 , as well as office space in London, United Kingdom, under a lease which extends through April 2016 , Taipei, Taiwan, under a lease which extends through August 2016 , Seoul, South Korea, under a lease which extends through August 2016 , Reston, Virginia, under a lease which extends through September 2020 , Galway, Ireland under a lease which extends through September 2016 and Dublin, Ireland under a month-to-month lease. Rent expense for non-cancellable operating leases with scheduled rent increases is recognized on a straight-line basis over the lease term. Rent expense was $0.7 million and $1.8 million for the three and nine months ended September 30, 2015 , respectively, compared to $0.4 million and $1.1 million for the three and nine months ended September 30, 2014 , respectively. Future minimum lease payments under the non-cancellable operating leases as of September 30, 2015 , are as follows (in thousands): Year Ending December 31, Amount 2015 (remaining 3 months) $ 566 2016 2,272 2017 1,993 2018 1,846 2019 694 Thereafter 228 Total future minimum lease payments $ 7,599 Capital Lease Obligations The Company has entered into certain capital lease obligations to purchase equipment for operations which include a bargain purchase option. The underlying assets and related depreciation are included in the appropriate property and equipment category and related accumulated depreciation account. Property and equipment includes amounts under leases that have been capitalized as follows (dollars in thousands): Useful life (Years) September 30, 2015 December 31, Computer equipment 3 $ 382 $ 382 Total capital leased equipment 382 382 Less: Accumulated depreciation and amortization (117 ) (21 ) Capital leased equipment, net $ 265 $ 361 Total amortization of assets acquired under capital leases was $32,000 and $0.1 million for the three and nine months ended September 30, 2015 , respectively, which is included in total depreciation and amortization expense. There were no such arrangements during the three and nine months ended September 30, 2014 . Future minimum payments required under capital leases as of September 30, 2015 , are as follows (in thousands): Year Ending December 31, Amount 2015 (remaining 3 months) $ 33 2016 132 2017 141 Total future payments $ 306 Less: Amount representing interest $ 13 Present value of future minimum payments 293 Less: Current portion 123 Long term portion $ 170 Purchase Commitments The Company had non-cancellable purchase obligations to contract manufacturers and suppliers of $11.9 million and $4.0 million at September 30, 2015 and December 31, 2014 , respectively. The $7.9 million increase in contract obligations from December 31, 2014 to September 30, 2015 was mainly due to inventory purchase commitments relating to the Company's launch of the CoolSmooth PRO and CoolMini, as well as in contemplation of future demand and sales levels. Unrecognized Tax Benefits The Company's gross liability for unrecognized tax benefits totaled $30,000 , including estimated interest and penalties, as of September 30, 2015 , and is classified in long-term income taxes payable. The Company is unable to make a reasonably reliable estimate of the timing of payments in individual years due to uncertainties in the timing of tax audits, if any, or their outcomes. Legal Matters From time to time, the Company may be involved in legal and administrative proceedings and claims of various types. The Company records a liability in its consolidated financial statements for these matters when a loss is known and considered probable and the amount can be reasonably estimated. Management reviews these estimates in each accounting period as additional information becomes known and adjusts the loss provision when appropriate. If the loss is not probable or cannot be reasonably estimated, a liability is not recorded in the consolidated financial statements. If a loss is probable but the amount of loss cannot be reasonably estimated, the Company discloses the loss contingency and an estimate of possible loss or range of loss (unless such an estimate cannot be made). The Company does not recognize gain contingencies until they are realized. Legal costs incurred in connection with loss contingencies are expensed as incurred. The Company is not currently a defendant in any litigation or claims that are expected to have a material impact on the Company's condensed consolidated financial statements. Product Liability Contingencies The Company has historically been and continues to be predominantly self-insured for any product liability losses related to its products. The Company obtains third-party insurance to limit its exposure to these claims, but this insurance is subject to a cap on reimbursement. Product liability losses are, by their nature, uncertain and are based upon complex judgments and probabilities. The Company accrues for reported claims and estimates for incurred, but not reported claims, to the extent that such losses can be reasonably estimated. The Company determines its accruals for probable product liability losses based on various factors, including historical claims and settlement experience. The total amount of self-insured product liability claims settled in the three and nine months ended September 30, 2015 were $0.3 million and $0.5 million , respectively. The total amount of self-insured product liability claims settled in the three and nine months ended September 30, 2014 were not material. The amount of reported and estimated incurred but not known self-insured product liability claims pending was $1.1 million as of September 30, 2015 , which is recorded as an accrual on the Company's condensed consolidated balance sheet. Such estimated claims were not significant as of December 31, 2014 . Indemnifications In the normal course of business, the Company enters into contracts that contain a variety of representations and warranties and provide for general indemnifications. The Company's exposure under these agreements is unknown because it involves claims that may be made against the Company in the future, but have not yet been made. To date, the Company has not paid any claims, and the Company believes that the estimated fair value of these indemnification obligations is minimal and it has not accrued any amounts for these obligations.

Stock-Based Compensation Expens

Stock-Based Compensation Expense	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Expense	Stock-Based Compensation Expense Stock-Based Compensation Activity Activity under the Company’s stock-based compensation plans is set forth below: Options Outstanding Shares Available for Grant Number of Stock Options Outstanding Weighted- Average Exercise Price Balance, December 31, 2014 2,685,209 3,242,421 $ 6.47 Additional shares reserved 1,000,000 — — Options granted (45,622 ) 45,622 34.65 Restricted stock units granted (536,639 ) — — Options exercised — (529,703 ) 5.61 Options canceled 37,520 (37,520 ) 8.55 Restricted stock units withheld for tax 203,043 — — Restricted stock units canceled 152,441 — — Balance, September 30, 2015 3,495,952 2,720,820 $ 7.03 Restricted Stock Activity Activity related to restricted stock units and awards is set forth below: Number of Units and Awards Weighted- Balance, December 31, 2014 1,533,081 $ 10.08 Restricted stock units granted 536,639 32.04 Restricted stock units vested (503,129 ) 9.94 Restricted stock units canceled (152,441 ) 13.50 Balance, September 30, 2015 1,414,150 $ 18.04 During the three and nine months ended September 30, 2015 , 71,521 and 503,129 shares vested, respectively, subject to previously granted restricted stock units. A majority of these vested restricted stock units were net share settled. During the three and nine months ended September 30, 2015 , the Company withheld 28,176 and 203,043 shares, respectively, based upon the Company's closing stock price on the vesting date to settle the employee's minimum statutory obligation for the applicable income and other employment taxes. During the three and nine months ended September 30, 2014 , 61,283 and 490,441 shares vested, respectively, subject to previously granted restricted stock units. A majority of these vested restricted stock units were net share settled. During the three and nine months ended September 30, 2014 , the Company withheld 24,848 and 201,702 shares, respectively, based upon the Company's closing stock price on the vesting date to settle the employee's minimum statutory obligation for the applicable income and other employment taxes. Subsequently, the Company remitted cash to the appropriate taxing authorities. Total payments for employee's tax obligations to the relevant taxing authority was $0.9 million and $6.5 million for the three and nine months ended September 30, 2015 , respectively. Total payments for employee's tax obligations to the relevant taxing authority was $0.5 million and $3.8 million for the three and nine months ended September 30, 2014 , respectively. The payments were for taxes related to the net share settlements of restricted stock units. Stock-Based Compensation Expense Stock-based compensation related to all of the Company's stock-based awards and employee stock purchases was recorded as an expense or a reduction to revenue and categorized as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Revenue $ 56 $ — $ 205 $ — Cost of revenue 234 115 517 325 Research and development 424 289 1,166 758 Sales and marketing 1,163 986 4,062 2,920 General and administrative 1,151 1,128 4,311 3,026 Total stock-based compensation $ 3,028 $ 2,518 $ 10,261 $ 7,029 As of September 30, 2015 , the total unrecognized compensation costs related to outstanding stock options, awards and employee stock purchases was $20.2 million , which is expected to be recognized using the straight-line attribution method over 1.3 years . Performance-Based Awards Stock-based compensation expense includes charges related to performance-based stock options and restricted stock units granted to certain executives. Stock-based compensation expense related to these stock options and restricted stock units was $0.3 million and $2.3 million for the three and nine months ended September 30, 2015 , respectively, compared to $0.4 million and $1.4 million for the three and nine months ended September 30, 2014 , respectively. Employee Stock-Based Compensation The Company uses the Black-Scholes option pricing model to determine the fair value of stock options. The valuation model for stock-based compensation expense requires the Company to make assumptions and judgments about the variables used in the calculation including the expected term (weighted-average period of time that the options granted are expected to be outstanding), volatility of the Company's common stock, an assumed-risk-free interest rate and the estimated forfeitures of unvested stock options. During 2015, the Company modified its approach for calculating assumptions related to the expected term and volatility as detailed below. The fair value of employee stock options was estimated using the following weighted-average assumptions: Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Expected term (in years) N/A N/A 4.8 4.4 Expected volatility N/A N/A 63 % 43 % Risk-free interest rate N/A N/A 1.29 % 1.21 % Expected dividend yield N/A N/A — % — % Expected Term . Prior to the Company's initial public offering of its common stock, or IPO, the Company derived the expected term using the “simplified” method (the expected term is determined as the average of the time-to-vesting and the contractual life of the options), as the Company had limited historical information to develop expectations about future exercise patterns and post-vesting employment termination behavior. Subsequent to the IPO and through 2014, the expected term used was based on expected term of a group of similar entities, referred to as its “peer group.” In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size. In 2015, the Company modified its approach by including its own historical data along with the expected term of the identified peer group companies. The Company will continue to apply this methodology until a sufficient amount of historical information regarding its own expected term becomes available. Volatility . Prior to the IPO, because the Company was a private entity with no historical data regarding the volatility of its common stock, the expected volatility used was based on volatility of a group of similar entities, referred to as its “peer group.” In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size. Subsequent to the IPO and through 2014, the Company continued to estimate its volatility based on its peer group as the Company did not have sufficient historical data regarding its specific volatility. In 2015, the Company modified its approach by including its own common stock trading history along with the volatility of the identified peer group companies. The expected stock price volatility is estimated using a combination of historical and peer group volatility to derive the expected volatility assumption. The Company believes the blended volatility is more representative of future stock price trends over the expected life of the options rather than just using historical or peer group volatility. The Company will continue to apply this methodology until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. Risk-Free Interest Rate . The risk-free interest rate is based on U.S. Treasury zero-coupon issues with remaining terms similar to the expected term on the options. Dividend Yield . The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future, and, therefore, used an expected dividend yield of zero in the valuation model. Forfeitures. The Company is required to estimate forfeitures at the time of grant, and revise those estimates in subsequent periods if actual forfeitures differ from those estimates. The Company uses historical data to estimate pre-vesting option forfeitures and to record stock-based compensation expense only for those awards that are expected to vest. To the extent actual forfeitures differ from the estimates, the difference will be recorded as a cumulative adjustment in the period that the estimates are revised. No stock options were granted in either of the three months ended September 30, 2015 or September 30, 2014 . During the nine months ended September 30, 2015 , the Company granted 45,622 stock options to employees with a weighted-average grant date fair value of $18.19 per share. During the nine months ended September 30, 2014 , the Company granted 250,000 stock options to employees with a weighted-average grant date fair value of $6.77 per share, respectively. During the three and nine months ended September 30, 2015 , the Company granted 109,667 and 536,639 restricted stock units, respectively, to employees with a weighted-average grant date fair value of $33.93 and $32.04 per share, respectively. During the three and nine months ended September 30, 2014 , the Company granted 31,500 and 400,675 restricted stock units, respectively, to employees with a weighted-average grant date fair value of $19.56 and $18.39 per share, respectively. During the nine months ended September 30, 2015 , employees purchased 52,965 shares under the Company's employee stock purchase plan, or ESPP, at a weighted average exercise price of $22.02 . As of September 30, 2015 , the unrecognized compensation cost related to the ESPP was $0.1 million , which will be recognized using the straight-line attribution method over 0.2 years . Stock-Based Compensation for Non-employees Stock-based compensation expense related to stock-based awards to non-employees is recognized as the stock-based awards are earned, generally through the provision of services. The Company believes that the fair value of the stock-based awards is more reliably measurable than the fair value of the services received. The fair value of the granted stock-based awards is calculated at each reporting date using the Black-Scholes option pricing model. During the three and nine months ended September 30, 2015 , the Company granted stock-based awards to a non-employee that vest over one year. During the three and nine months ended September 30, 2014 , the Company granted stock-based awards to a non-employee which will vest over two years . Stock-based compensation expense related to non-employee grants was $0.1 million and $0.4 million for the three and nine months ended September 30, 2015 , respectively, of which $0.1 million and $0.2 million relates to an arrangement with a non-employee customer and has been recorded as a reduction of revenue for both the three and nine months ended September 30, 2015 , respectively, in the condensed consolidated statements of operations. Stock-based compensation expense for non-employees was $0.3 million and $0.4 million for the three and nine months ended September 30, 2014 , respectively.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) per Share Basic net income (loss) per share is calculated by dividing the net income (loss) by the weighted-average number of shares of common stock outstanding for the period. Diluted net income (loss) per share is computed by giving effect to all potentially dilutive securities outstanding during the period, including stock options, restricted stock units and common stock issuable pursuant to the ESPP. A reconciliation of the numerator and denominator used in the calculation of the basic and diluted net income (loss) per share is as follows: Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Numerator Net income (in thousands) $ 2,147 $ 4,782 $ 1,196 $ 214 Denominator Weighted average shares of common stock outstanding used in computing net income per share, basic 38,881,183 37,630,222 38,640,269 37,430,337 Dilutive effect of incremental shares and share equivalents 1,979,410 3,295,812 2,083,992 3,350,804 Weighted average shares of common stock outstanding used in computing net income per share, diluted 40,860,593 40,926,034 40,724,261 40,781,141 Net income (loss) per share: Net income per share, basic $ 0.06 $ 0.13 $ 0.03 $ 0.01 Net income per share, diluted $ 0.05 $ 0.12 $ 0.03 $ 0.01 Basic net income per share is computed using the weighted average number of common shares outstanding during the period. Diluted net income per share is computed using the treasury stock method to calculate the weighted average number of common shares and, if dilutive, potential common shares outstanding during the period. Potential dilutive common shares include unvested restricted stock awards and units and incremental common shares issuable upon the exercise of stock options, less shares from assumed proceeds. The assumed proceeds calculation includes actual proceeds to be received from the employee upon exercise, the average unrecognized stock compensation cost during the period and any tax benefits that will be credited upon exercise to additional paid-in capital. The following outstanding potentially dilutive securities were excluded from the computation of diluted net income (loss) per share of common stock for the periods presented, because including them would have been anti-dilutive: Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Options to purchase common stock 45,622 305,000 37,433 192,308 Restricted stock units 19,810 — 8,154 84,361 Common stock issuable pursuant to the ESPP — — — — Total 65,432 305,000 45,587 276,669

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded income tax expense of $0.2 million for both the three and nine months ended September 30, 2015 , respectively, compared to income tax expense of $7,000 and $13,000 for the three and nine months ended September 30, 2014 , respectively. The income tax expense for the three and nine months ended September 30, 2015 and 2014 reflects federal and state alternative minimum tax, as well as income tax expense related to the Company's operating jurisdictions. The Company continues to maintain a valuation allowance for its U.S. federal and state deferred tax assets. At September 30, 2015 , the Company had $1.6 million of unrecognized tax benefits, of which $29,000 , if recognized, would affect the effective tax rate due to the valuation allowance that currently offsets deferred tax assets. The Company recognizes interest and penalties related to uncertain tax positions as part of the income tax provision. To date, such interest and penalties have not been material. The Company maintains a full valuation allowance on its deferred tax assets until there is sufficient evidence to support the reversal of all or some portion of these allowances. However, considering the Company's current assessment of the probability of maintaining profitability, there is a reasonable possibility that, in the near term, sufficient positive evidence may become available to reach a conclusion that a significant portion, or all, of the valuation allowance will no longer be needed. In that case, the Company may release a significant portion, or all, of its valuation allowance against its deferred tax assets. This release would result in the recognition of certain deferred tax assets an equal benefit to income tax expense in the period such release is recorded. The Company files annual income tax returns in multiple taxing jurisdictions around the world, including the U.S. federal and state jurisdictions, Ireland, and the United Kingdom. A number of years may elapse before an uncertain tax position is audited and finally resolved. While it is often difficult to predict the final outcome or the timing of resolution of any particular uncertain tax position, the Company believes that its reserves for income taxes reflect the most likely outcome. The Company adjusts these reserves, as well as the related interest, in light of changing facts and circumstances. Settlement of any particular position could require the use of cash. As of September 30, 2015 , changes to the Company's uncertain tax positions in the next 12 months that are reasonably possible are not expected to have a significant impact on the Company's financial position or results of operations.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment Information	Segment Information Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or decision making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The Company has one business activity and there are no segment managers who are held accountable for operations. Accordingly, the Company has a single reportable segment structure. All of the Company’s principal operations and decision-making functions are located in the United States. The Company’s revenue by geographic region, based on the location to where the product was shipped, is summarized as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 North America $ 46,602 $ 34,964 $ 133,267 $ 94,828 International 14,600 10,706 43,924 28,878 Total $ 61,202 $ 45,670 $ 177,191 $ 123,706 North America includes the United States and related territories, as well as Canada. International is the rest of the world. Revenue for the United States was $42.4 million and $122.9 million for the three and nine months ended September 30, 2015 , respectively, compared to $32.2 million and $88.1 million for the three and nine months ended September 30, 2014 , respectively. The following table sets forth revenue by product expressed as dollar amounts (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 System revenue $ 29,298 $ 24,783 $ 87,501 $ 64,627 Consumable revenue 31,904 20,887 89,690 59,079 Total $ 61,202 $ 45,670 $ 177,191 $ 123,706 Substantially all of the Company’s long-lived assets are located in the United States of America.

Basis of Presentation and Sum17

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim condensed consolidated financial statements of ZELTIQ Aesthetics, Inc. (the "Company") are unaudited. These interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP, and the applicable rules and regulations of the Securities and Exchange Commission, or SEC, for interim financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. The December 31, 2014 condensed consolidated balance sheet was derived from the audited financial statements as of that date, but does not include all of the information and footnotes required by GAAP for complete financial statements. The accompanying unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments of a normal recurring nature considered necessary to state fairly the Company's financial position as of September 30, 2015 , results of operations for the three and nine months ended September 30, 2015 and 2014 , comprehensive income (loss) for the three and nine months ended September 30, 2015 and 2014 , and cash flows for the nine months ended September 30, 2015 and 2014 . The interim results for the three and nine months ended September 30, 2015 , are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 , or for any other future annual or interim period. Certain amounts in the prior year's condensed consolidated balance sheet have been reclassified to conform to the current period's presentation. These reclassifications had no impact on previously reported condensed consolidated statements of cash flows or statements of operations. 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 the Company's Annual Report on Form 10-K for the year ended December 31, 2014 .
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.
Foreign Currency	The functional currency of the Company’s international subsidiaries is evaluated on a case-by-case basis and has been determined to be the respective local currency. All assets and liabilities of these foreign operations are translated to U.S. Dollars at current period end exchange rates, and revenue and expenses are translated to U.S. Dollars using average exchange rates in effect during the period. The gains and losses from the foreign currency translation of the foreign subsidiaries' financial statements are included as a separate component of stockholders' equity under "Accumulated other comprehensive income (loss)." Gains or losses arising from currency exchange rate fluctuations on transactions denominated in a currency other than the local functional currency are included in other income (expense), net.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reported periods. The primary estimates underlying the Company's financial statements include the value of revenue elements, product warranty, inventory valuation, allowance for doubtful accounts receivable, assumptions regarding variables used in calculating the fair value of the Company's equity awards, fair value of investments, useful lives of intangibles, income taxes and contingent liabilities. Actual results could differ from those estimates.
Critical Accounting Policies	Critical Accounting Policies There have been no changes to the Company’s critical accounting policies during the nine months ended September 30, 2015 , as compared to the critical accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 .
Recent Accounting Pronouncements	Recent Accounting Pronouncements On May 28, 2014 , the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers. The objective of this update is to provide a single, comprehensive revenue recognition model for all contracts with customers to improve comparability within industries, across industries, and across capital markets. This standard update contains principles that the Company will apply to determine the measurement of revenue and timing of when it is recognized. This guidance allows for two methods of adoption: (a) full retrospective adoption, meaning the guidance is applied to all periods presented, or (b) modified retrospective adoption, meaning the cumulative effect of applying this guidance is recognized as an adjustment to the fiscal 2018 opening Accumulated deficit balance. The Company expects to adopt this guidance effective January 1, 2018 , and is currently evaluating the two adoption methods as well as the impact this new guidance will have on its consolidated financial statements and related disclosures. In August 2014 , the FASB issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties About an Entity's Ability to Continue as a Going Concern. This standard update provides guidance around management's responsibility to evaluate whether there is substantial doubt about an entity's ability to continue as a going concern and to provide related footnote disclosures. The new guidance is effective for all annual and interim periods ending after December 15, 2016 . The new guidance is not expected to have an impact on the Company's consolidated financial statements and related disclosures. In April 2015 , the FASB issued Accounting Standards Update No. 2015-05 regarding Subtopic 350-40, “Intangibles - Goodwill and Other - Internal-Use Software.” This standard provides guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The amendments are effective for annual and interim periods beginning after December 15, 2015 . Early adoption is permitted. The amendments may be applied either prospectively to all arrangements entered into or materially modified after the effective date or retrospectively. The Company is currently evaluating the impact this new guidance will have on its consolidated financial statements and related disclosures. In June 2015 , the FASB issued Accounting Standards Update No. 2015-10, Technical Corrections and Improvements. The standard covers a wide range of Topics in the Codification. The amendments in this standard represent changes to clarify the Codification, correct unintended application of guidance, or make minor improvements to the Codification that are not expected to have a significant effect on current accounting practice or create a significant administrative cost on most entities. The amendments are effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2015 . The Company does not anticipate that the adoption of this standard will have a material impact on its consolidated financial statements and footnote disclosures. The Company is currently evaluating the impact this new guidance will have on its consolidated financial statements and related disclosures. In July 2015 , the FASB amended ASC Topic 330, Inventory ("ASC 330") to simplify the measurement of inventory. The amendments require that an entity measure inventory at the lower of cost and net realizable value instead of the lower of cost and market. This guidance is effective for public companies for years, and interim periods within those years, beginning on or after December 15, 2016, with earlier application permitted as of the beginning of an interim or annual reporting period. This guidance will be effective for the Company beginning in its first quarter of fiscal 2017. The Company is currently evaluating the impact this new guidance will have on its consolidated financial statements and related disclosures.
Fair Value of Financial Instruments	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices 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 assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The categorization of a financial instrument within the valuation hierarchy is based on the lowest level of input that is significant to the fair value measurement.
Inventory	Inventory is stated at the lower of cost (which approximates actual cost on a first-in, first-out basis) or market. Inventory that is obsolete or in excess of forecasted usage is written down to its estimated net realizable value based on assumptions about future demand, new production introductions and market conditions.

Fair Value of Financial Instr18

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair value of financial assets and liabilities by level within fair value hierarchy	The following tables set forth the fair value of the Company’s financial assets and liabilities by level within the fair value hierarchy (in thousands): As of September 30, 2015 Level 1 Level 2 Level 3 Fair Value Financial Assets Cash equivalents: Money market funds $ 6,371 $ — $ — $ 6,371 Commercial paper — 500 — 500 Short-term investments: U.S. Agency securities — 1,651 — 1,651 U.S. Treasury — 500 — 500 Corporate bonds — 6,869 — 6,869 Commercial paper — 500 — 500 Certificates of deposit 1,715 — — 1,715 Long-term investments: U.S. Agency securities — 250 — 250 Corporate bonds — 611 — 611 Certificates of deposit 2,759 — — 2,759 Total $ 10,845 $ 10,881 $ — $ 21,726 As of December 31, 2014 Level 1 Level 2 Level 3 Fair Value Financial Assets Cash equivalents: Money market funds $ 6,062 $ — $ — $ 6,062 Short-term investments: U.S. Agency securities — 5,240 — 5,240 U.S. Treasury — 1,004 — 1,004 Corporate bonds — 7,774 — 7,774 Commercial paper — 1,349 — 1,349 Certificates of deposit 919 — — 919 Long-term investments: U.S. Agency securities — 999 — 999 U.S. Treasury — 500 — 500 Corporate bonds — 750 — 750 Certificates of deposit 2,556 — — 2,556 Total $ 9,537 $ 17,616 $ — $ 27,153

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Investments	The Company's short-term and long-term investments as of September 30, 2015 are as follows (in thousands): Short-term Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Agency securities $ 1,651 $ — $ — $ 1,651 U.S. Treasury 500 — — 500 Corporate bonds 6,868 2 (1 ) 6,869 Commercial paper 500 — — 500 Certificates of deposit 1,715 — — 1,715 Total $ 11,234 $ 2 $ (1 ) $ 11,235 Long-term Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Agency securities $ 250 $ — $ — $ 250 Corporate bonds 612 — (1 ) 611 Certificates of deposit 2,759 — — 2,759 Total $ 3,621 $ — $ (1 ) $ 3,620 The Company's short-term and long-term investments as of December 31, 2014 are as follows (in thousands): Short-term Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Agency securities $ 5,240 $ 1 $ (1 ) $ 5,240 U.S. Treasury 1,003 1 — 1,004 Corporate bonds 7,778 2 (6 ) 7,774 Commercial paper 1,349 — — 1,349 Certificates of deposit 919 — — 919 Total $ 16,289 $ 4 $ (7 ) $ 16,286 Long-term Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Agency securities $ 1,000 $ — $ (1 ) $ 999 U.S. Treasury 500 — — 500 Corporate bonds 752 — (2 ) 750 Certificates of deposit 2,556 — — 2,556 Total $ 4,808 $ — $ (3 ) $ 4,805
Schedule of Contractual Maturities of Investments	The contractual maturities of the Company's short-term and long-term investments as of September 30, 2015 , are as follows (in thousands): September 30, 2015 Amortized Cost Fair Value Due in one year or less $ 11,234 $ 11,235 Due in one year to five years 3,621 3,620 $ 14,855 $ 14,855
Schedule of Inventory	The components of inventory consist of the following (in thousands): September 30, December 31, Raw materials $ 10,354 $ 7,692 Finished goods 18,429 7,844 Total inventory $ 28,783 $ 15,536
Schedule of Property and Equipment, Net	Property and equipment, net comprised the following (in thousands): September 30, December 31, Lab equipment, tooling and molds $ 3,221 $ 2,766 Computer software 2,072 1,337 Computer equipment 1,443 984 Leasehold improvements 1,708 1,452 Furniture and fixtures 924 494 Vehicles 51 35 Total property and equipment 9,419 7,068 Less: Accumulated depreciation and amortization (5,224 ) (4,111 ) Construction in progress 575 767 Property and equipment, net $ 4,770 $ 3,724
Schedule of Accrued Liabilities	The following table shows the components of accrued liabilities (in thousands): September 30, December 31, Accrued payroll and employee related expenses $ 11,930 $ 8,386 Accrued marketing expenses 5,031 2,959 Accrued royalty 4,142 3,612 Sales and other taxes payable 2,929 2,123 Advance payments from customers 4,200 1,908 Accrued warranty 536 569 Accrued legal expenses 2,114 592 Other 1,137 1,301 Total accrued and other current liabilities $ 32,019 $ 21,450
Schedule of Product Warranty Accrual	The product warranty accrual was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Balance at the beginning of the period $ 339 $ 741 $ 569 $ 676 Warranty costs incurred (377 ) (170 ) (721 ) (643 ) Net changes in liability for pre-existing warranties, including expirations 516 18 520 423 Provision for warranty 58 112 168 245 Balance at the end of the period $ 536 $ 701 $ 536 $ 701

Intangible Asset, Net (Tables)

Intangible Asset, Net (Tables)	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets, Net	Intangible asset, net comprised the following (in thousands): September 30, December 31, Purchased technology $ 8,050 $ 8,050 Less: Accumulated amortization (2,795 ) (2,270 ) Intangible asset, net $ 5,255 $ 5,780
Schedule of Total Estimated Annual Future Amortization Expense	The total estimated annual future amortization expense of this intangible asset as of September 30, 2015 , is as follows (in thousands): Fiscal Year 2015 (remaining 3 months) $ 176 2016 701 2017 701 2018 701 2019 701 Thereafter 2,275 Total $ 5,255

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum lease payments under the non-cancellable operating leases as of September 30, 2015 , are as follows (in thousands): Year Ending December 31, Amount 2015 (remaining 3 months) $ 566 2016 2,272 2017 1,993 2018 1,846 2019 694 Thereafter 228 Total future minimum lease payments $ 7,599
Schedule of Capital Leased Assets	Property and equipment includes amounts under leases that have been capitalized as follows (dollars in thousands): Useful life (Years) September 30, 2015 December 31, Computer equipment 3 $ 382 $ 382 Total capital leased equipment 382 382 Less: Accumulated depreciation and amortization (117 ) (21 ) Capital leased equipment, net $ 265 $ 361
Schedule of Future Minimum Payments Required Under Capital Leases	Future minimum payments required under capital leases as of September 30, 2015 , are as follows (in thousands): Year Ending December 31, Amount 2015 (remaining 3 months) $ 33 2016 132 2017 141 Total future payments $ 306 Less: Amount representing interest $ 13 Present value of future minimum payments 293 Less: Current portion 123 Long term portion $ 170

Stock-Based Compensation Expe22

Stock-Based Compensation Expense (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Options Activity	Activity under the Company’s stock-based compensation plans is set forth below: Options Outstanding Shares Available for Grant Number of Stock Options Outstanding Weighted- Average Exercise Price Balance, December 31, 2014 2,685,209 3,242,421 $ 6.47 Additional shares reserved 1,000,000 — — Options granted (45,622 ) 45,622 34.65 Restricted stock units granted (536,639 ) — — Options exercised — (529,703 ) 5.61 Options canceled 37,520 (37,520 ) 8.55 Restricted stock units withheld for tax 203,043 — — Restricted stock units canceled 152,441 — — Balance, September 30, 2015 3,495,952 2,720,820 $ 7.03
Restricted Stock Activity	Activity related to restricted stock units and awards is set forth below: Number of Units and Awards Weighted- Balance, December 31, 2014 1,533,081 $ 10.08 Restricted stock units granted 536,639 32.04 Restricted stock units vested (503,129 ) 9.94 Restricted stock units canceled (152,441 ) 13.50 Balance, September 30, 2015 1,414,150 $ 18.04
Stock-based Compensation Expense	Stock-based compensation related to all of the Company's stock-based awards and employee stock purchases was recorded as an expense or a reduction to revenue and categorized as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Revenue $ 56 $ — $ 205 $ — Cost of revenue 234 115 517 325 Research and development 424 289 1,166 758 Sales and marketing 1,163 986 4,062 2,920 General and administrative 1,151 1,128 4,311 3,026 Total stock-based compensation $ 3,028 $ 2,518 $ 10,261 $ 7,029
Summary of Fair Value of Employee Stock Option Assumptions	The fair value of employee stock options was estimated using the following weighted-average assumptions: Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Expected term (in years) N/A N/A 4.8 4.4 Expected volatility N/A N/A 63 % 43 % Risk-free interest rate N/A N/A 1.29 % 1.21 % Expected dividend yield N/A N/A — % — %

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	A reconciliation of the numerator and denominator used in the calculation of the basic and diluted net income (loss) per share is as follows: Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Numerator Net income (in thousands) $ 2,147 $ 4,782 $ 1,196 $ 214 Denominator Weighted average shares of common stock outstanding used in computing net income per share, basic 38,881,183 37,630,222 38,640,269 37,430,337 Dilutive effect of incremental shares and share equivalents 1,979,410 3,295,812 2,083,992 3,350,804 Weighted average shares of common stock outstanding used in computing net income per share, diluted 40,860,593 40,926,034 40,724,261 40,781,141 Net income (loss) per share: Net income per share, basic $ 0.06 $ 0.13 $ 0.03 $ 0.01 Net income per share, diluted $ 0.05 $ 0.12 $ 0.03 $ 0.01
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following outstanding potentially dilutive securities were excluded from the computation of diluted net income (loss) per share of common stock for the periods presented, because including them would have been anti-dilutive: Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Options to purchase common stock 45,622 305,000 37,433 192,308 Restricted stock units 19,810 — 8,154 84,361 Common stock issuable pursuant to the ESPP — — — — Total 65,432 305,000 45,587 276,669

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Revenue By Geographic Region	The Company’s revenue by geographic region, based on the location to where the product was shipped, is summarized as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 North America $ 46,602 $ 34,964 $ 133,267 $ 94,828 International 14,600 10,706 43,924 28,878 Total $ 61,202 $ 45,670 $ 177,191 $ 123,706
Revenue By Product	The following table sets forth revenue by product expressed as dollar amounts (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 System revenue $ 29,298 $ 24,783 $ 87,501 $ 64,627 Consumable revenue 31,904 20,887 89,690 59,079 Total $ 61,202 $ 45,670 $ 177,191 $ 123,706

Basis of Presentation and Sum25

Basis of Presentation and Summary of Significant Accounting Policies - Out of Period Adjustments (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenue	$ 16,041		$ 12,555	$ 48,535	$ 35,231
Overstatement of Inventory and Understatement of Cost of Revenue [Member] | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenue		$ 200
Overstatement of Inventory and Understatement of Cost of Revenue [Member] | Restatement Adjustment [Member] | Adjustment Related to Fiscal 2012 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenue		100
Overstatement of Inventory and Understatement of Cost of Revenue [Member] | Restatement Adjustment [Member] | Adjustment Related to Fiscal 2013 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenue		23
Overstatement of Inventory and Understatement of Cost of Revenue [Member] | Restatement Adjustment [Member] | Adjustment Related to Fiscal 2014 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenue		$ 42

Basis of Presentation and Sum26

Basis of Presentation and Summary of Significant Accounting Policies - Concentration of Credit Risk (Details) - Customer Concentration Risk [Member] - customer	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration risk, number	1	1
Concentration risk, percentage	27.00%	24.00%
Revenue [Member]
Concentration Risk [Line Items]
Concentration risk, number	1
Concentration risk, percentage	12.00%

Fair Value of Financial Instr27

Fair Value of Financial Instruments (Details) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 14,855,000
Assets, fair value disclosure	21,726,000	$ 27,153,000
Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	6,371,000	6,062,000
Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	500,000
Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	11,235,000	16,286,000
Short-term Investments [Member] | U.S. Agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	1,651,000	5,240,000
Short-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	500,000	1,004,000
Short-term Investments [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	6,869,000	7,774,000
Short-term Investments [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	500,000	1,349,000
Short-term Investments [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	1,715,000	919,000
Long-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	3,620,000	4,805,000
Long-term Investments [Member] | U.S. Agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	250,000	999,000
Long-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure		500,000
Long-term Investments [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	611,000	750,000
Long-term Investments [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	2,759,000	2,556,000
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	10,845,000	9,537,000
Level 1 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	6,371,000	6,062,000
Level 1 [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	0
Level 1 [Member] | Short-term Investments [Member] | U.S. Agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 1 [Member] | Short-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 1 [Member] | Short-term Investments [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 1 [Member] | Short-term Investments [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 1 [Member] | Short-term Investments [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	1,715,000	919,000
Level 1 [Member] | Long-term Investments [Member] | U.S. Agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 1 [Member] | Long-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure		0
Level 1 [Member] | Long-term Investments [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 1 [Member] | Long-term Investments [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	2,759,000	2,556,000
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	10,881,000	17,616,000
Level 2 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	0	0
Level 2 [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	500,000
Level 2 [Member] | Short-term Investments [Member] | U.S. Agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	1,651,000	5,240,000
Level 2 [Member] | Short-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	500,000	1,004,000
Level 2 [Member] | Short-term Investments [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	6,869,000	7,774,000
Level 2 [Member] | Short-term Investments [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	500,000	1,349,000
Level 2 [Member] | Short-term Investments [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 2 [Member] | Long-term Investments [Member] | U.S. Agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	250,000	999,000
Level 2 [Member] | Long-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure		500,000
Level 2 [Member] | Long-term Investments [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	611,000	750,000
Level 2 [Member] | Long-term Investments [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Liabilities, fair value disclosure	0	0
Level 3 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	0	0
Level 3 [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	0
Level 3 [Member] | Short-term Investments [Member] | U.S. Agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 3 [Member] | Short-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 3 [Member] | Short-term Investments [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 3 [Member] | Short-term Investments [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 3 [Member] | Short-term Investments [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 3 [Member] | Long-term Investments [Member] | U.S. Agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 3 [Member] | Long-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure		0
Level 3 [Member] | Long-term Investments [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	0	0
Level 3 [Member] | Long-term Investments [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 0	$ 0

Balance Sheet Components - Inve

Balance Sheet Components - Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 14,855
Fair Value	14,855
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,234	$ 16,289
Gross Unrealized Gains	2	4
Gross Unrealized Losses	(1)	(7)
Fair Value	11,235	16,286
Short-term Investments [Member] | U.S. Agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,651	5,240
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	(1)
Fair Value	1,651	5,240
Short-term Investments [Member] | U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	500	1,003
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Fair Value	500	1,004
Short-term Investments [Member] | Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,868	7,778
Gross Unrealized Gains	2	2
Gross Unrealized Losses	(1)	(6)
Fair Value	6,869	7,774
Short-term Investments [Member] | Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	500	1,349
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	500	1,349
Short-term Investments [Member] | Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,715	919
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	1,715	919
Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,621	4,808
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(3)
Fair Value	3,620	4,805
Long-term Investments [Member] | U.S. Agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	250	1,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(1)
Fair Value	250	999
Long-term Investments [Member] | U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		500
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		500
Long-term Investments [Member] | Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	612	752
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(2)
Fair Value	611	750
Long-term Investments [Member] | Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,759	2,556
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 2,759	$ 2,556

Balance Sheet Components - In29

Balance Sheet Components - Investments, Contractual Maturities (Details) $ in Thousands	Sep. 30, 2015USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Amortized Cost, Due in one year or less	$ 11,234
Amortized Cost, Due in one year to five years	3,621
Amortized Cost	14,855
Fair Value, Due in one year or less	11,235
Fair Value, Due in one year to five years	3,620
Fair Value	$ 14,855

Balance Sheet Components - In30

Balance Sheet Components - Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Inventory, Net [Abstract]
Raw materials	$ 10,354	$ 7,692
Finished goods	18,429	7,844
Total inventory	$ 28,783	$ 15,536

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 9,419		$ 9,419		$ 7,068
Less: Accumulated depreciation and amortization	(5,224)		(5,224)		(4,111)
Property and equipment, net	4,770		4,770		3,724
Property and equipment acquired under capital leases	382		382		382
Depreciation expense	500	$ 200	1,200	$ 800
Lab equipment, tooling and molds [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,221		3,221		2,766
Computer software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,072		2,072		1,337
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,443		1,443		984
Property and equipment acquired under capital leases	382		382		382
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,708		1,708		1,452
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	924		924		494
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	51		51		35
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 575		$ 575		$ 767

Balance Sheet Components - Accr

Balance Sheet Components - Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued payroll and employee related expenses	$ 11,930	$ 8,386
Accrued marketing expenses	5,031	2,959
Accrued royalty	4,142	3,612
Sales and other taxes payable	2,929	2,123
Advance payments from customers	4,200	1,908
Accrued warranty	536	569
Accrued legal expenses	2,114	592
Other	1,137	1,301
Total accrued and other current liabilities	$ 32,019	$ 21,450

Balance Sheet Components - Prod

Balance Sheet Components - Product Warranty (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at the beginning of the period	$ 339	$ 741	$ 569	$ 676
Warranty costs incurred	(377)	(170)	(721)	(643)
Net changes in liability for pre-existing warranties, including expirations	516	18	520	423
Provision for warranty	58	112	168	245
Balance at the end of the period	$ 536	$ 701	$ 536	$ 701
Direct Customer [Member] | Control Units [Member]
Product Liability Contingency [Line Items]
Product Warranty Accrual, Term			1 year
Direct Customer [Member] | Applicators [Member]
Product Liability Contingency [Line Items]
Product Warranty Accrual, Term			1 year
International [Member] | Indirect Customer [Member] | Control Units [Member]
Product Liability Contingency [Line Items]
Product Warranty Accrual, Term			3 years
International [Member] | Indirect Customer [Member] | Applicators [Member]
Product Liability Contingency [Line Items]
Product Warranty Accrual, Term			1 year

Intangible Asset, Net - Amortiz

Intangible Asset, Net - Amortization (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 0.2	$ 0.2	$ 0.5	$ 0.5

Intangible Asset, Net - Compone

Intangible Asset, Net - Components (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Purchased technology	$ 8,050	$ 8,050
Less: Accumulated amortization	(2,795)	(2,270)
Intangible asset, net	$ 5,255	$ 5,780

Intangible Asset, Net - Estimat

Intangible Asset, Net - Estimated Annual Future Amortization Expense (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Intangible Asset, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2015 (remaining 3 months)	$ 176
2,016	701
2,017	701
2,018	701
2,019	701
Thereafter	2,275
Intangible asset, net	$ 5,255	$ 5,780

Related Party Transactions - Br

Related Party Transactions - Brazilian Distribution Agreement (Details) - Distributor [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Related Party Transaction [Line Items]
Payments term, maximum			180 days
Revenue from related parties	$ 1.4	$ 0.2	$ 2.9	$ 1.3
Accounts receivable, related parties	$ 1.7		$ 1.7		$ 0.2

Commitments and Contingencies -

Commitments and Contingencies - Operating Lease Obligations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 700	$ 400	$ 1,800	$ 1,100
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2015 (remaining 3 months)	566		566
2,016	2,272		2,272
2,017	1,993		1,993
2,018	1,846		1,846
2,019	694		694
Thereafter	228		228
Total future minimum lease payments	$ 7,599		$ 7,599

Commitments and Contingencies39

Commitments and Contingencies - Capital Lease Obligations (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Capital Leased Assets [Line Items]
Capital leased equipment, gross	$ 382,000		$ 382,000		$ 382,000
Less: Accumulated depreciation and amortization	(117,000)		(117,000)		(21,000)
Capital leased equipment, net	265,000		265,000		361,000
Amortization of assets acquired under capital leases	32,000	$ 0	100,000	$ 0
Future minimum payments under capital leases
2015 (remaining 3 months)	33,000		33,000
2,016	132,000		132,000
2,017	141,000		141,000
Total future payments	306,000		306,000
Less: Amount representing interest	13,000		13,000
Present value of future minimum payments	293,000		293,000
Less: Current portion	123,000		123,000		120,000
Long term portion	170,000		$ 170,000		262,000
Computer equipment [Member]
Capital Leased Assets [Line Items]
Useful Life			3 years
Capital leased equipment, gross	$ 382,000		$ 382,000		$ 382,000

Commitments and Contingencies40

Commitments and Contingencies - Purchase Commitments, Unrecognized Tax Benefits, and Product Liability Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Purchase obligation	$ 11,900	$ 11,900	$ 4,000
Increase in contract obligations		7,900
Unrecognized tax benefits, including estimated interest and penalties	30	30
Product liability claims settled	300	500
Known and reasonably estimable self-insured product liability claims pending	$ 1,100	$ 1,100

Stock-Based Compensation Expe41

Stock-Based Compensation Expense - Stock Options Plan Activity (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Shares Available for Grant
Balance at beginning of period (Shares)			2,685,209
Additional shares reserved (Shares)			1,000,000
Options granted (Shares)	0	0	(45,622)	(250,000)
Options canceled (Shares)			37,520
Balance at end of period (Shares)	3,495,952		3,495,952
Number of Stock Options Outstanding
Balance at beginning of period (Shares)			3,242,421
Options granted (Shares)	0	0	45,622	250,000
Options exercised (Shares)			(529,703)
Options canceled (Shares)			(37,520)
Balance at end of period (Shares)	2,720,820		2,720,820
Weighted-Average Exercise Price
Balance at beginning of period (Weighted average exercise price) (In Dollars per Share)			$ 6.47
Options granted (Weighted average exercise price) (In Dollars per Share)			34.65
Options exercised (Weighted average exercise price) (In Dollars per Share)			5.61
Options canceled (Weighted average exercise price) (In Dollars per Share)			8.55
Balance at end of period (Weighted average exercise price) (In Dollars per Share)	$ 7.03		$ 7.03
Restricted Stock Units (RSUs) [Member]
Shares Available for Grant
Restricted stock units granted (Shares)			(536,639)
Restricted stock units withheld for tax (Shares)	28,176	24,848	203,043	201,702
Restricted stock units canceled (Shares)			152,441

Stock-Based Compensation Expe42

Stock-Based Compensation Expense - Restricted Stock Units (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Weighted- Average Grant Date Fair Value
Payments for employee's tax obligations to relevant taxing authority			$ 6,577	$ 3,774
Restricted Stock Units (RSUs) [Member]
Number of Units and Awards
Balance at beginning of period (Shares)			1,533,081
Restricted stock units granted (Shares)			536,639
Restricted stock units vested (Shares)	(71,521)	(61,283)	(503,129)	(490,441)
Restricted stock units canceled (Shares)			(152,441)
Balance at end of period (Shares)	1,414,150		1,414,150
Weighted- Average Grant Date Fair Value
Balance at beginning of period (Weighted average exercise price) (In Dollars per Share)			$ 10.08
Restricted stock units granted (Weighted average exercise price) (In Dollars per Share)			32.04
Restricted stock units vested (Weighted average exercise price) (In Dollars per Share)			9.94
Restricted stock units canceled (Weighted average exercise price) (In Dollars per Share)			13.50
Balance at end of period (Weighted average exercise price) (In Dollars per Share)	$ 18.04		$ 18.04
Restricted stock units withheld for tax (Shares)	28,176	24,848	203,043	201,702
Payments for employee's tax obligations to relevant taxing authority	$ 900	$ 500	$ 6,500	$ 3,800

Stock-Based Compensation Expe43

Stock-Based Compensation Expense - Allocation of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,028	$ 2,518	$ 10,261	$ 7,029
Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	56	0	205	0
Cost of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	234	115	517	325
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	424	289	1,166	758
Sales and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,163	986	4,062	2,920
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,151	1,128	4,311	3,026
Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	20,200		$ 20,200
Unrecognized compensation cost, recognition period (in years)			1 year 3 months 18 days
Performance Based Stock Options and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 300	$ 400	$ 2,300	$ 1,400

Stock-Based Compensation Expe44

Stock-Based Compensation Expense - Assumptions (Details) - Stock Options [Member]	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	4 years 9 months 18 days	4 years 4 months 24 days
Expected volatility	63.00%	43.00%
Risk-free interest rate	1.29%	1.21%
Expected dividend yield	0.00%	0.00%

Stock-Based Compensation Expe45

Stock-Based Compensation Expense - Employee Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (Shares)	0	0	45,622	250,000
Weighted average grant date fair value, Options (In Dollars per Share)			$ 18.19	$ 6.77
Employee Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units granted (Shares)	109,667	31,500	536,639	400,675
Weighted average grant date fair value (In Dollars per Share)	$ 33.93	$ 19.56	$ 32.04	$ 18.39
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased under employee stock purchase plan			52,965
Weighted average exercise price of shares purchased under employee stock purchase plan (in Dollars per Share)	$ 22.02		$ 22.02
Unrecognized compensation cost	$ 0.1		$ 0.1
Unrecognized compensation cost, recognition period (in years)			2 months

Stock-Based Compensation Expe46

Stock-Based Compensation Expense - Non-Employee Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,028	$ 2,518	$ 10,261	$ 7,029
Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 56	$ 0	$ 205	$ 0
Non-Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for non-employee stock-based awards	1 year	2 years	1 year	2 years
Stock-based compensation expense related to non-employee grants	$ 100	$ 300	$ 400	$ 400
Non-Employee [Member] | Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 100		$ 200

Net Income (Loss) Per Share (De

Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator
Net income	$ 2,147	$ 4,782	$ 1,196	$ 214
Denominator
Weighted average shares of common stock outstanding used in computing net income (loss) per share, basic	38,881,183	37,630,222	38,640,269	37,430,337
Dilutive effect of incremental shares and share equivalents	1,979,410	3,295,812	2,083,992	3,350,804
Weighted average shares of common stock outstanding used in computing net income per share, diluted	40,860,593	40,926,034	40,724,261	40,781,141
Net income (loss) per share:
Net income per share, basic (dollars per share)	$ 0.06	$ 0.13	$ 0.03	$ 0.01
Net income per share, diluted (dollars per share)	$ 0.05	$ 0.12	$ 0.03	$ 0.01

Net Income (Loss) Per Share - O

Net Income (Loss) Per Share - Outstanding Shares of Potentially Dilutive Securities (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	65,432	305,000	45,587	276,669
Options to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	45,622	305,000	37,433	192,308
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	19,810	0	8,154	84,361
Common stock issuable pursuant to the ESPP [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0	0	0	0

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Income tax (benefit) expense	$ 160	$ 7	$ 231	$ 13
Unrecognized tax benefits	1,600		1,600
Unrecognized tax benefits that would impact effective tax rate	$ 29		$ 29

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)segmentmanagerbusiness_activity	Sep. 30, 2014USD ($)
Segment Reporting Information [Line Items]
Number of business activities | business_activity			1
Number of segment managers held accountable for operations | manager			0
Number of reportable segments | segment			1
Revenue, net	$ 61,202	$ 45,670	$ 177,191	$ 123,706
Systems Revenue [Member]
Segment Reporting Information [Line Items]
Revenue, net	29,298	24,783	87,501	64,627
Consumable Revenue [Member]
Segment Reporting Information [Line Items]
Revenue, net	31,904	20,887	89,690	59,079
North America [Member]
Segment Reporting Information [Line Items]
Revenue, net	46,602	34,964	133,267	94,828
United States [Member]
Segment Reporting Information [Line Items]
Revenue, net	42,400	32,200	122,900	88,100
International [Member]
Segment Reporting Information [Line Items]
Revenue, net	$ 14,600	$ 10,706	$ 43,924	$ 28,878