ZELTIQ Aesthetics (ZLTQ) 10-K 10 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Mar. 03, 2015	Jun. 30, 2014
Document and Entity Information: [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Entity Registrant Name	Zeltiq Aesthetics Inc
Entity Central Index Key	1415336
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding		38,450,883
Entity Public Float			$443,413,963

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:
Cash and cash equivalents	$28,649	$25,798
Short-term investments	16,286	18,840
Accounts receivable, net	21,472	10,221
Inventory	15,536	8,406
Prepaid expenses and other current assets	7,060	4,368
Total current assets	89,003	67,633
Long-term investments	4,805	11,442
Restricted cash	560	331
Property and equipment, net	3,724	2,158
Intangible asset, net	5,780	6,481
Other assets	33	9
Total assets	103,905	88,054
CURRENT LIABILITIES:
Accounts payable	5,824	5,165
Accrued liabilities	21,450	18,364
Deferred revenue	5,069	1,674
Current portion of capital lease obligations	120	0
Total current liabilities	32,463	25,203
Long-term capital lease obligations, less current portion	262	0
Other non-current liabilities	661	275
Total liabilities	33,386	25,478
Commitments and contingencies
STOCKHOLDERS’ EQUITY:
Preferred stock, $0.01 par value: 50,000,000 shares authorized and no shares issued and outstanding at December 31, 2014, and December 31, 2013	0	0
Common stock, $0.001 par value: 500,000,000 shares authorized at December 31, 2014, and December 31, 2013; 38,123,998 and 37,038,374 shares issued and outstanding at December 31, 2014, and December 31, 2013, respectively	42	41
Additional paid-in capital	202,701	195,507
Accumulated other comprehensive income (loss)	-696	87
Accumulated deficit	-131,528	-133,059
Total stockholders’ equity	70,519	62,576
Total liabilities and stockholders’ equity	$103,905	$88,054

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Preferred stock, par value (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 (dollars per share)	$0.00	$0.00
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	38,123,998	37,038,374
Common stock, shares outstanding	38,123,998	37,038,374

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Revenue	$174,478	$111,626	$76,194
Cost of revenue	50,064	34,189	25,506
Gross profit	124,414	77,437	50,688
Operating expenses:
Research and development	18,196	17,090	12,693
Sales and marketing	83,579	63,185	51,167
General and administrative	20,515	16,510	16,867
Total operating expenses	122,290	96,785	80,727
Income (loss) from operations	2,124	-19,348	-30,039
Interest income (expense), net	63	80	129
Other income (expense), net	-425	103	-92
Income (loss) before income taxes	1,762	-19,165	-30,002
Income tax expense	231	140	141
Net income (loss)	$1,531	($19,305)	($30,143)
Basic net income (loss) per share:
Net income (loss) per share, basic (in dollars per share)	$0.04	($0.53)	($0.87)
Weighted average shares of common stock outstanding used in computing net income (loss) per share, basic	37,563,590	36,209,051	34,776,380
Diluted net income (loss) per share:
Net income (loss) per share, diluted (in dollars per share)	$0.04	($0.53)	($0.87)
Weighted average shares of common stock outstanding used in computing net income (loss) per share, diluted	40,996,972	36,209,051	34,776,380

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income (loss)	$1,531	($19,305)	($30,143)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	-767	77	0
Changes in unrealized gains (losses) on available-for-sale securities	-16	2	8
Other comprehensive income (loss), net of tax	-783	79	8
Comprehensive income (loss)	$748	($19,226)	($30,135)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Note Receivable From Stockholder [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2011	$94,303,000	$37,000	$178,122,000	($245,000)	$0	($83,611,000)
Balance, shares at Dec. 31, 2011		33,997,809
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options	2,669,000	2,000	2,667,000
Issuance of common stock upon exercise of stock options, shares		1,612,233
Issuance of common stock in connection with ESPP	497,000	0	497,000
Issuance of common stock in connection with ESPP, shares		133,363
Proceeds for repayment of notes receivable from a stockholder	245,000			245,000
Issuance of common stock upon vesting of RSUs	0	0
Issuance of common stock upon vesting of RSUs, shares		106,959
Issuance of common stock in exchange for services	12,000	0	12,000
Issuance of common stock in exchange for services, shares		1,741
Stock-based compensation	4,989,000		4,989,000
Change in unrealized gain (loss) on marketable securities, net of tax	8,000				8,000
Currency translation adjustments, net of tax	0
Net income (loss)	-30,143,000					-30,143,000
Comprehensive income (loss)	-30,135,000
Balance at Dec. 31, 2012	72,580,000	39,000	186,287,000	0	8,000	-113,754,000
Balance, shares at Dec. 31, 2012		35,852,105
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options	2,647,000	2,000	2,645,000
Issuance of common stock upon exercise of stock options, shares	791,198	791,198
Issuance of common stock in connection with ESPP	791,000		791,000
Issuance of common stock in connection with ESPP, shares		188,467
Issuance of common stock upon vesting of RSUs, shares		292,265
Common stock traded for employee tax obligation	-876,000		-876,000
Common stock traded for employee tax obligation, shares		-85,661
Stock-based compensation	6,660,000		6,660,000
Change in unrealized gain (loss) on marketable securities, net of tax	2,000				2,000
Currency translation adjustments, net of tax	77,000				77,000
Net income (loss)	-19,305,000					-19,305,000
Comprehensive income (loss)	-19,226,000
Balance at Dec. 31, 2013	62,576,000	41,000	195,507,000	0	87,000	-133,059,000
Balance, shares at Dec. 31, 2013		37,038,374
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options	2,787,000	1,000	2,786,000
Issuance of common stock upon exercise of stock options, shares	569,283	569,283
Issuance of common stock in connection with ESPP	1,532,000		1,532,000
Issuance of common stock in connection with ESPP, shares		103,089
Issuance of common stock upon vesting of RSUs, shares		724,400
Common stock traded for employee tax obligation	-6,594,000		-6,594,000
Common stock traded for employee tax obligation, shares		-311,148
Stock-based compensation	9,383,000		9,383,000
Tax benefit from employee stock plans	87,000		87,000
Change in unrealized gain (loss) on marketable securities, net of tax	-16,000				-16,000
Currency translation adjustments, net of tax	-767,000				-767,000
Net income (loss)	1,531,000					1,531,000
Comprehensive income (loss)	748,000
Balance at Dec. 31, 2014	$70,519,000	$42,000	$202,701,000	$0	($696,000)	($131,528,000)
Balance, shares at Dec. 31, 2014		38,123,998

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$1,531	($19,305)	($30,143)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	1,824	1,729	1,602
Stock-based compensation	9,383	6,660	4,989
Deferred income taxes	-19	19	-66
Amortization (accretion) of investment premium (discount), net	221	343	212
Provision for (recovery of) doubtful accounts receivable	324	-12	290
Issuance of common stock for services	0	0	12
Provision for excess and obsolete inventory	853	262	300
Loss on disposal and write-off of property and equipment	46	2	192
Changes in operating assets and liabilities:
Accounts receivable	-11,219	-3,064	-2,482
Inventory	-6,898	2,225	-6,695
Prepaid expenses and other assets	-2,419	-693	-1,240
Deferred revenue, net of deferred costs	2,908	267	1,026
Accounts payable, accrued and other non-current liabilities	2,609	7,486	5,377
Net cash provided by (used in) operating activities	-856	-4,081	-26,626
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of investments	-13,444	-31,591	-58,658
Proceeds from sale of investments	1,000	11,143	9,250
Proceeds from maturity of investments	21,393	25,528	13,500
Purchase of property and equipment	-2,340	-834	-1,385
Change in restricted cash	-252	138	-214
Net cash provided by (used in) investing activities	6,357	4,384	-37,507
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of notes payable	0	0	-310
Proceeds from repayment of note receivable by a stockholder	0	0	245
Proceeds from issuance of common stock upon exercise of stock options	4,319	3,438	3,166
Tax payments related to shares withheld for vested restricted stock units	-6,594	-876	0
Tax effect of employee stock plans	87	0	0
Net cash provided by (used in) financing activities	-2,188	2,562	3,101
Effect of exchange rate on cash and cash equivalents	-462	57	0
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	2,851	2,922	-61,032
CASH AND CASH EQUIVALENTS—Beginning of period	25,798	22,876	83,908
CASH AND CASH EQUIVALENTS—End of period	$28,649	$25,798	$22,876

The_Company_and_Basis_of_Prese

The Company and Basis of Presentation	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company and Basis of Presentation	The Company and Basis of Presentation
	ZELTIQ Aesthetics, Inc. (the “Company”) was incorporated in the state of Delaware on March 22, 2005. The Company was founded to develop and commercialize a non-invasive product for the selective reduction of fat. Its first commercial product, the CoolSculpting system, is designed to selectively reduce stubborn fat bulges. CoolSculpting is based on the scientific principle that fat cells are more sensitive to cold than the overlying skin and surrounding tissues. CoolSculpting utilizes precisely controlled cooling to reduce the temperature of fat cells in the treated area, which leads to fat cell elimination through a natural biological process known as apoptosis, without causing scar tissue or damage to the skin, nerves, or surrounding tissues. The Company generates revenue from sales of its CoolSculpting system and from sales of consumables to its customers.
	In August 2011, the Company incorporated ZELTIQ Limited as a wholly-owned subsidiary in the United Kingdom to serve as its sales office for direct sales in Europe. In December 2014, the Company incorporated ZELTIQ Ireland Limited and ZELTIQ Ireland International Limited as wholly-owned subsidiaries in Ireland for additional office support in Europe.
	Out of period adjustments
	During the three months ended December 31, 2014, the Company recorded and corrected an adjustment related to stock-based compensation that resulted in $0.7 million of revenue reduction. The adjustment to revenue resulted from an error in the application of generally accepted accounting principles related to payments to customers for services starting in the second quarter of 2013 through the third quarter of 2014. Of the total amount of this adjustment, $0.4 million related to the fiscal year ending December 31, 2013. The error caused the overstatement of revenue and sales and marketing expense in prior periods due to the missclassification of this stock-based compensation. This adjustment did not have any impact to the Company's consolidated net income (loss) as reported in the consolidated statements of operations in any current or prior interim or annual period. The Company does not believe that such amounts are material to current and previously reported consolidated financial statements.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP.
	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.
	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.
	Significant Risks and Uncertainties
	The Company's future results of operations involve a number of risks and uncertainties. Factors that could affect the Company's future operating results and cause actual results to vary materially from expectations include, but are not limited to, rapid technological change, continued acceptance of the Company's products, competition from substitute products and larger companies, ability to protect proprietary technology from copy-cat or counterfeit versions the Company's products, strategic relationships and dependence on key individuals. If the Company fails to adhere to ongoing Food and Drug Administration, or FDA, Quality System Regulation, the FDA may withdraw its market clearance or take other action. The Company relies on sole-source suppliers to manufacture some of the components used in its product. The Company's manufacturers and suppliers may encounter supply interruptions or problems during manufacturing due to a variety of reasons, including failure to comply with applicable regulations, including the FDA's Quality System Regulation, equipment malfunction and environmental factors, any of which could delay or impede the Company's ability to meet demand.
	Concentration of Credit Risk
	Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash equivalents, marketable securities and trade receivables. The Company's cash equivalents and marketable securities are held in safekeeping by large, credit worthy financial institutions. The Company invests its excess cash primarily in U.S. banks, government and agency bonds, money market funds and corporate obligations. The Company has established guidelines relative to credit ratings, diversification and maturities that seek to maintain safety and liquidity. Deposits in these banks may exceed the amounts of insurance provided on such deposits. To date, the Company has not experienced any losses on its deposits of cash and cash equivalents.
	The Company controls credit risk through credit approvals, credit limits, and monitoring procedures. The Company performs periodic credit evaluations of its customers and generally does not require collateral. Accounts receivable are recorded net of an allowance for doubtful accounts. The allowance for doubtful accounts is based on management's assessment of the collectability of specific customer accounts and the aging of the related invoices, and represents the Company's best estimate of probable credit losses in its existing trade accounts receivable. At December 31, 2014, the Company's allowance for doubtful accounts was $0.3 million. The Company did not have an allowance for doubtful accounts as of December 31, 2013.
	The allowance for doubtful accounts consisted of the following activity for fiscal years ended December 31, 2014, 2013 and 2012 (in thousands):
	Description		Balance at Beginning of Year			Additions		Reductions		Balance at End of Year
	Year ended December 31, 2012		$	40		$	329	$	39	$	330
	Year ended December 31, 2013		330			59		389		—
	Year ended December 31, 2014		—			469		145		324
	As of December 31, 2014, one individual customer, which is a large aesthetic chain, comprised 24% of accounts receivable. No other individual customer accounted for 10% or more of the Company's accounts receivable. As of December 31, 2013, no individual customer accounted for 10% or more of the Company's accounts receivable. Furthermore, no individual customer accounted for greater than 10% of total revenue during the years ended December 31, 2014, 2013 and 2012, respectively.
	Cash and Cash Equivalents
	The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents.
	Investments
	The Company invests its excess cash balances primarily in certificates of deposit, commercial paper, corporate bonds, and U.S. Government agency securities. Investments with original maturities greater than 90 days that mature less than one year from the consolidated balance sheet date are classified as short-term investments. The Company classifies all of its investments as available-for-sale and records such assets at estimated fair value in the consolidated balance sheets, with unrealized gains and losses, if any, reported as a component of accumulated other comprehensive income (loss) in stockholders' equity. Realized gains and losses from maturities of all such securities are reported in earnings and computed using the specific identification cost method.  Realized gains or losses and charges for other-than-temporary declines in value, if any, on available-for-sale securities are reported in other income (expense), net as incurred.  The Company periodically evaluates these investments for other-than-temporary impairment.
	Inventory
	Inventory is stated at the lower of cost (which approximates actual cost on a first-in, first-out basis) or market, computed on a standard cost basis. 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 and market conditions. Inventory write-downs are charged to cost of revenue and establish a new cost basis for the inventory.
	Property and Equipment
	Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Maintenance and repairs are charged to expense as incurred. Assets not yet placed in use are not depreciated.
	The useful lives of the property and equipment are as follows:
	Lab equipment, tooling, and molds	5 years
	Computer equipment	3 years
	Computer software	3 years
	Furniture and fixtures	5 years
	Vehicles	5 years
	Leasehold improvements	Shorter of lease term or estimated useful life
	Capitalized Software
	The Company capitalizes costs associated with customized internal-use software systems that have reached the application development stage and meet recoverability tests. Such capitalized costs mainly include external direct costs utilized in developing or obtaining the applications. Capitalization of such costs begins when the preliminary project stage is complete and ceases at the point in which the project is substantially complete and is ready for its intended purpose. The capitalized costs associated with internal-use software are depreciated on a straight-line basis over each asset's estimated useful life, which is generally three years.
	Restricted Cash
	At December 31, 2014 and 2013, cash of $0.6 million and $0.3 million, respectively, was restricted from withdrawal and held by banks in the form of certificates of deposit. At December 31, 2014 and 2013, the certificates of deposit were held as collateral for the facility lease agreement in Pleasanton, California, and for its United Kingdom banking facilities and credit card programs.
	Intangible Asset
	The intangible asset consists of an exclusive license agreement for commercializing patents and other technology. All milestone payments subsequent to the date of the FDA approval are 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.
	Impairment of Long-lived Assets
	The Company reviews property and equipment and the intangible asset for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future undiscounted net cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the assets' fair value determined using the projected discounted future net cash flows arising from the asset.
	Through December 31, 2014, there have been no such impairments.
	Revenue Recognition
	The Company’s revenue is derived from the sales of the CoolSculpting system, consisting of a control unit and applicators, and, from time to time, related extended warranty arrangements, and from the sale of cycles in the form of consumable procedure packs, each of which includes consumable CoolGels, CoolLiners, and in the case of the Company's CoolSmooth procedure packs, disposable securement accessories, all of which are used by the Company's customer during treatments. In addition, each consumable procedure pack includes a disposable computer cartridge that the Company markets as the CoolCard. The CoolCard contains enabling software that permits the Company's customers to perform a fixed number of CoolSculpting procedures, or cycles. This software is not marketed separately from the CoolSculpting system or from the CoolCard. Rather, the functionality that the software provides is part of the overall CoolCard product. The CoolSculpting system is marketed as a non-invasive aesthetic device for the selective reduction of fat, not for its embedded software attributes included in the CoolCard that enable its use. The Company does not provide rights to upgrades and enhancements or post-contract customer support for the embedded software. In addition, the Company does not incur significant software development costs or capitalize its software development costs. Based on this assessment, the Company considers the embedded software in the CoolCard incidental to the CoolCard product as a whole and determined that revenue recognition should not be governed by the provisions of Topic 985 of the FASB Accounting Standards Codification, or ASC. The Company earns revenue from the sale of its products to its customers and to distributors. The Company recognizes revenue when persuasive evidence of an arrangement exists, transfer of title to the customer has occurred, the sales price is fixed or determinable, and collectability is probable. Revenue is deferred in the event that any of the revenue recognition criteria is not met.
	Persuasive Evidence of an Arrangement. The Company uses contracts or customer purchase orders to determine the existence of an arrangement.
	Transfer of title. The Company's standard terms specify that title transfers upon shipment to the customer. The Company uses third party shipping documents to verify that title has transferred.
	Sales Price Fixed or Determinable. The Company assesses whether the sales price is fixed or determinable at the time of the transaction. Sales prices are documented in the executed sales contract or purchase order received prior to shipment. The Company’s standard terms do not allow for trial or evaluation periods, rights of return or refund, payments contingent upon the customer obtaining financing or other terms that could impact the customer’s obligation.
	Collectability. The Company assesses whether collection is reasonably assured based on a number of factors, including the customer’s past transaction history and credit worthiness.
	Multiple-Element Arrangements. Typically, all products sold to a customer are delivered at the same time. If a partial delivery occurs as authorized by the customer, the Company allocates revenue to the various products based on their vendor-specific objective evidence of fair value, or VSOE, if VSOE exists according to ASC 605-25 as the basis of determining the relative selling price of each element. If VSOE does not exist, the Company may use third party evidence of fair value, or TPE, to determine the relative selling price of each element. If neither VSOE nor TPE exists, the Company may use management’s best estimate of the sales price, or ESP, of each element to determine the relative selling price. The relative selling prices for control units, applicators, CoolCards and extended warranty are based on established price lists and separate, stand-alone sales of these elements. The Company establishes best estimates within a range of selling prices considering multiple factors including, but not limited to, factors such as size of transaction, pricing strategies and market conditions. The Company believes the use of the ESP allows revenue recognition in a manner consistent with the underlying economics of the transaction. The Company’s products do not require maintenance or support. In a multiple-element arrangement, revenue is deferred for undelivered elements, which are generally training or extended warranty. Revenue on undelivered elements of an arrangement is recognized when all revenue recognition criteria have been met.
	Customer Programs and Payments
	Accruals for Customer Programs
	The Company records an accrued liability for cooperative marketing arrangements and customer incentive programs. The estimated cost of these programs is recorded as a reduction of revenue or as an operating expense, if the Company receives a separately identifiable benefit from the customer and can reasonably estimate the fair value of that benefit. Significant management judgment and estimates must be used to determine the cost of these programs in any accounting period.
	Cooperative Marketing Arrangements.  The Company offers cooperative marketing programs to its North American customers, allowing the customer to receive partial reimbursement for qualifying advertising expenditures which promote the Company's product and brand. Customer participation, as well as reimbursement amounts, is predicated upon purchase levels of CoolCards. The objective of these arrangements is to encourage advertising and promotional events to increase sales of the Company's products. Accruals for these marketing arrangements are recorded at the time of sale, or time of commitment, based on the related program parameters, review of related advertising and historical experience.
	Customer Incentive Programs. The Company's customer incentive program consists of rebates for its North American customers based on purchase levels of CoolCards. Estimated costs of consumer rebates and similar incentives are recorded at the time the incentive is offered, based on the specific terms and conditions of the program.
	Accounting for Payments to Customers
	The Company occasionally enters into transactions where it provides consideration to its customers in the forms of cash payments or stock-based awards in exchange for certain goods and services. The Company accounts for such payments to customers in accordance with ASC 605-50, Revenue Recognition: Customer Payments and Incentives, which requires the Company to characterize the payment as a reduction of revenue if the Company is unable to demonstrate the receipt of a benefit that is identifiable and sufficiently separable from the revenue transaction and reasonably estimate the fair value of the benefit identified. Significant management judgment and estimates must be used to determine the fair value of the benefit received in any period. For stock awards, the Company believes that the fair value of the awards is more reliably measured than the fair value of the benefit received. The fair value of the stock awards is measured as of the date at which either the commitment for performance by the customer to earn the award is reached or the date the customer’s performance is complete. Until that point is reached, the award is revalued at each reporting period with the true-up to fair value recorded in current period earnings.
	Cost of Revenue
	Cost of revenue consists primarily of cost of finished and semi-finished products purchased from the Company's third-party suppliers, labor, material, and overhead involved in its internal manufacturing processes, technology amortization and royalty fees and cost of product warranty. In the event that a revenue transaction is deferred, the corresponding cost associated with the transaction will also be deferred.
	Shipping and Handling
	Shipping and handling costs charged to customers are recorded as revenue. Shipping costs are included in cost of revenue.
	Research and Development
	Research and development costs primarily consist of salaries, benefits, incentive compensation, stock-based compensation, and allocated facilities costs for employees and contractors engaged in research, clinical studies, regulatory affairs, and development. The Company expenses all research and development costs in the periods in which they are incurred.
	Advertising costs
	The cost of advertising and media is expensed as incurred. For the years ended December 31, 2014, 2013 and 2012, advertising costs totaled $7.9 million, $8.9 million and $12.0 million, respectively.
Product Warranty
The Company provides a standard limited warranty on its products of 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 approximately three years for control units and one year for applicators.
The Company accrues for the estimated future costs of repair or replacement upon shipment. The warranty accrual is 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 Company offers an extended warranty on both its CoolSculpting control units and CoolSculpting applicators. The Company recognizes the revenue from the sale of an extended warranty over the extended warranty coverage period. The Company's revenue and related obligations from sale of extended warranties to date has not been significant.
Stock-Based Compensation
The Company maintains incentive plans under which incentive and nonqualified stock options are granted primarily to employees and non-employee consultants.
Stock-based compensation cost is measured at the grant date, based on the fair value of the award, and is recognized as expense on a straight-line basis over the requisite service period. The fair value of stock-based awards to employees is estimated using the Black-Scholes option pricing model. The Company estimates its forfeiture rate based on an analysis of its actual forfeitures and will continue to evaluate the adequacy of the forfeiture rate assumption based on actual forfeitures, analysis of employee turnover, and other related factors.
Stock-based compensation expense related to stock options granted to non-employees is recognized as the stock options are earned. The awards generally vest ratably over the time period the Company expects to receive services from the non-employee. The fair values attributable to these options are amortized over the service period and the unvested portion of these options is remeasured at each vesting date.
Income Taxes
The Company utilizes the asset and liability method of accounting for income taxes, under which deferred taxes are determined based on the temporary differences between the financial statement and tax basis of assets and liabilities using tax rates expected to be in effect during the years in which the basis differences reverse and for operating losses and tax credit carryforwards. The Company estimates its income taxes and amounts ultimately payable or recoverable in multiple tax jurisdictions around the world. Estimates involve interpretations of regulations and are inherently complex. Resolution of income tax treatments in individual jurisdictions may not be known for many years after completion of any fiscal year. The Company is required to evaluate the realizability of its deferred tax assets on an ongoing basis to determine whether there is a need for a valuation allowance with respect to such deferred tax assets. A valuation allowance is recorded when it is more likely than not that some or all of the deferred tax assets will not be realized. Significant management judgment is required in determining any valuation allowance recorded against deferred tax assets. In evaluating the ability to recover deferred tax assets, the Company considers all available positive and negative evidence giving greater weight to its recent cumulative losses and its ability to carryback losses against prior taxable income and, commensurate with objective verifiability, the forecast of future taxable income including the reversal of temporary differences and the implementation of feasible and prudent tax planning strategies.
The Company recognizes and measures uncertain tax positions taken or expected to be taken in a tax return if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such positions are then measured based on the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate settlement. The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in a tax return. The Company adjusts these reserves in light of changing facts and circumstances, such as the closing of a tax audit or the refinement of an estimate. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will impact the provision for income taxes in the period in which such determination is made. The provision for income taxes includes the impact of reserve provisions and changes to reserves that are considered appropriate, as well as the related net interest. The Company recognizes interest and penalties related to unrecognized tax benefits within the income tax provision. Accrued interest and penalties are included within the related tax liability line in the consolidated balance sheet.
The Company files annual income tax returns in multiple taxing jurisdictions around the world. 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.
Net Income (Loss) Per Share
Basic net income (loss) per share of common stock 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 of common stock is computed by giving effect to all potentially dilutive securities outstanding during the period, including options, restricted stock units and common stock issuable pursuant to the ESPP.
Comprehensive Income (Loss)
Accumulated other comprehensive income (loss) includes foreign currency translation adjustments and unrealized gains (losses) on available-for-sale securities net of tax, the impact of which has been excluded from earnings and reflected as components of stockholders' equity.
Components of accumulated other comprehensive income (loss) was as follows (in thousands):
	December 31,
	2014			2013
Cumulative translation adjustments	$	(690	)	$	77
Unrealized gain (loss) on marketable securities, net of tax	(6		)	10
Accumulated other comprehensive income (loss)	$	(696	)	$	87
Foreign currency translation
Based on an evaluation of economic facts and circumstances together with the functional currency analysis prescribed in ASC 830, Foreign Currency Matters, on October 1, 2013, the Company changed the functional and reporting currency for its operations in the United Kingdom from the U.S. Dollar to the British Pound. Such change did not have a material impact on the consolidated financial statements of the Company. The functional and reporting currency is the Euro for the Company's operations in Ireland and the U.S. dollar for all of its other foreign operations.
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. For the years ended December 31, 2014, 2013 and 2012, such amount totaled $(0.3) million, $24,000 and $(48,000), respectively.
Recent Accounting Pronouncements
On May 28, 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update No. 2014-10, 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. The Company will adopt this guidance effective January 1, 2017, and is currently assessing the impact it may have on the Company's consolidated financial statements.
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 will not have an impact on the Company's consolidated financial statements.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2014
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 Company did not hold any Level 3 assets or liabilities at December 31, 2014.
	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 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
		As of December 31, 2013
		Level 1		Level 2		Level 3		Fair Value
	Financial Assets
	Cash equivalents:
	Money market funds	$	12,796	$	—	$	—	$	12,796
	Short-term investments:
	U.S. Agency securities	—		6,772		—		6,772
	U.S. Treasury	—		1,001		—		1,001
	Corporate bonds	—		8,870		—		8,870
	Commercial paper	—		999		—		999
	Certificates of deposit	1,198		—		—		1,198
	Long-term investments:
	U.S. Agency securities	—		6,956		—		6,956
	U.S. Treasury	—		1,014		—		1,014
	Corporate bonds	—		2,795		—		2,795
	Certificates of deposit	677		—		—		677
	Total	$	14,671	$	28,407	$	—	$	43,078
	During the years ended December 31, 2014, and 2013, 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 December 31, 2014, and December 31, 2013.
	The carrying amounts of the Company’s cash equivalents, accounts receivable, accounts payable and accrued liabilities, approximate fair value due to their relatively short maturities.

Balance_Sheet_Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2014
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 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
	The Company's short-term and long-term investments as of December 31, 2013, are as follows (in thousands):
	Short-term
		Amortized Cost			Gross Unrealized Gains			Gross Unrealized Losses			Fair Value
	U.S. Agency securities	$	6,771		$	2		$	(1	)	$	6,772
	U.S. Treasury	1,000			1			—			1,001
	Corporate bonds	8,867			3			—			8,870
	Commercial paper	999			—			—			999
	Certificates of deposit	1,198			—			—			1,198
	Total	$	18,835		$	6		$	(1	)	$	18,840
	Long-term
		Amortized Cost			Gross Unrealized Gains			Gross Unrealized Losses			Fair Value
	U.S. Agency securities	$	6,957		$	2		$	(3	)	$	6,956
	U.S. Treasury	1,013			1			—			1,014
	Corporate bonds	2,790			5			—			2,795
	Certificates of deposit	677			—			—			677
	Total	$	11,437		$	8		$	(3	)	$	11,442
	For the years ended December 31, 2014, and December 31, 2013, 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 December 31, 2014, are as follows (in thousands):
		December 31, 2014
		Amortized Cost			Fair Value
	Due in one year or less	$	16,289		$	16,286
	Due in one year to five years	4,808			4,805
		$	21,097		$	21,091
	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, computed on a standard cost basis. 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 and market conditions.
	The components of inventory consist of the following (in thousands):
		December 31,
		2014			2013
	Raw materials	$	7,692		$	4,520
	Finished goods	7,844			3,886
	Total inventory	$	15,536		$	8,406
	Property and equipment, net
	Property and equipment, net comprised the following (in thousands):
		December 31,
		2014			2013
	Lab equipment, tooling and molds	$	2,766		$	2,071
	Computer software	1,337			1,562
	Computer equipment	984			801
	Leasehold improvements	1,452			743
	Furniture and fixtures	494			334
	Vehicles	35			35
	Total property and equipment	7,068			5,546
	Less: Accumulated depreciation and amortization	(4,111		)	(3,594		)
	Construction in progress	767			206
	Property and equipment, net	$	3,724		$	2,158
The table above includes property and equipment acquired under capital leases which totaled $0.4 million as of December 31, 2014.
Depreciation and amortization expense related to property and equipment was $1.1 million, $1.0 million and $0.9 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Accrued Liabilities
The following table shows the components of accrued liabilities (in thousands):
	December 31,
	2014			2013
Accrued payroll and employee related expenses	$	8,386		$	7,863
Accrued marketing expenses	2,959			3,739
Accrued royalty	3,612			2,458
Sales and other taxes payable	2,123			1,787
Advance payments from customers	1,908			1,216
Accrued warranty	569			676
Accrued legal expenses	592			284
Other accrued liabilities	1,301			341
Total accrued liabilities	$	21,450		$	18,364
Product Warranty
The estimated product warranty accrual was as follows (in thousands):
	December 31,
	2014			2013
Balance at the beginning of the period	$	676		$	902
Accruals for warranties issued	284			197
Settlements of warranty claims	(391		)	(423		)
Balance at the end of the period	$	569		$	676

License_Agreement_With_Massach

License Agreement With Massachusetts General Hospital	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
License Agreement with Massachusetts General Hospital	License Agreement with Massachusetts General Hospital
	In May 2005, the Company entered into an exclusive license agreement with the General Hospital Corporation, a not for profit Massachusetts corporation, which owns and operates the Massachusetts General Hospital, or MGH. This agreement was amended and restated in September 2011. Under this agreement, the Company obtained an exclusive license to develop and commercialize the patent and the core technology that underlies its CoolSculpting system. The Company conducted development from 2005 through 2009, and thereafter started commercialization of the products. The agreement will remain in full force and effect for the later of (i) the life of any patents that issue from the underlying patent applications, which are expected to expire in 2023 or (ii) one year after the last commercial sale for which a royalty is due to MGH, unless terminated in accordance with its terms and conditions. MGH may terminate the agreement upon the Company's insolvency, failure to maintain insurance, material breach of the agreement including failure to satisfy the Company's post-sales requirements, or failure to make required payments. The Company may terminate the agreement for any reason upon 90 days' advance written notice to MGH. The Company has complied with its contractual requirements to date.
	The Company is obligated to make various payments to MGH, including (i) a 7% royalty on net sales (as defined in the agreement) of CoolSculpting and (ii) milestone payments. During the year ended December 31, 2010, the Company paid MGH a $1.1 million milestone payment upon receipt of Food and Drug Administration, or FDA, clearance to market its CoolSculpting system for the selective reduction of fat. The remaining milestone payments including (i) $1 million due upon achieving cumulative net sales (as defined in the agreement) of $70 million and (ii) $6 million due upon the earlier to occur of achieving cumulative net sales (as defined in the agreement) of $200 million, or the completion of a qualifying initial public offering were made during the quarter ended December 31, 2011. As of December 31, 2011, the Company had completed all the milestones associated with the license agreement with MGH and had no milestone payments to MGH outstanding.
	All payments made to MGH prior to the FDA product clearance are expensed as incurred as research and development costs. All milestone payments payable by the Company pursuant to the terms of the agreement subsequent to the date of the 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. Royalty payments are accrued as the Company recognizes revenue, and are included in cost of revenue.
	The intangible asset, net comprised the following (in thousands):
		December 31,			December 31,
		2014			2013
	Purchased technology	$	8,050		$	8,050
	Less: Accumulated amortization	(2,270		)	(1,569		)
	Intangible asset, net	$	5,780		$	6,481
	The amortization expense of the intangible asset was $0.7 million for each of the years ended December 31, 2014, 2013 and 2012.
	The total estimated annual future amortization expense of this intangible asset as of December 31, 2014, is as follows (in thousands):
	Fiscal Year
	2015	$	701
	2016	701
	2017	701
	2018	701
	2019	701
	Thereafter	2,275
	Total	$	5,780

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
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 and amended on February 27, 2012 and September 4, 2012, appointing ADVANCE as the exclusive distributor of CoolSculpting in Brazil and Mexico. As of November 2014, ADVANCE is no longer a distributor in Mexico. 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. The revenue recognized by the Company under this distribution agreement for the years ended December 31, 2014, 2013 and 2012, was $2.1 million, $2.3 million and $2.5 million, respectively. The accounts receivable balance under this distribution agreement as of December 31, 2014 and 2013, was $0.2 million and $0.2 million, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
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 December 2015, and a warehouse space in Livermore, California, under a lease which extends through December 2015. 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 2015, Taipei, Taiwan, under a lease which extends through August 2016, Seoul, South Korea, under a lease which extends through October 2015, Reston, Virginia, under a lease which extends through August 2020, 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 for the years ended December 31, 2014, 2013 and 2012, was $1.5 million, $1.4 million and $1.2 million, respectively.
	Future minimum lease payments under the non-cancellable operating leases as of December 31, 2014, are as follows (in thousands):
	Year Ending December 31,	Amount
	2015	$	1,844
	2016	1,591
	2017	1,624
	2018	1,666
	2019	507
	Thereafter	84
	Total future minimum lease payments	$	7,316
	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 the following amounts under leases that have been capitalized as of December 31, 2014, as follows (in thousands):
		Useful life (Years)		December 31,
				2014
	Computer equipment	3		382
	Total capital leased equipment			382
	Less: Accumulated depreciation and amortization			(21		)
	Capital leased equipment, net			$	361
	Total amortization of assets acquired under capital leases was $21,000 for the year ended December 31, 2014, which is included in total depreciation and amortization expense. There were no such arrangements during the years ended December 31, 2013 and December 31, 2012.
	Future minimum payments required under capital leases as of December 31, 2014, are as follows (in thousands):
	Year Ending December 31,	Amount
	2015	$	132
	2016	132
	2017	141
	Total future payments	$	405
	Less: Amount representing interest	$	23
	Present value of future minimum payments	382
	Less: Current portion	120
	Long term portion	$	262
	Purchase Commitments
	The Company had non-cancellable purchase obligations to contract manufacturers and suppliers for $4.0 million and $6.0 million at December 31, 2014 and 2013, respectively.
	Unrecognized Tax Benefits
	The Company's gross liability for unrecognized tax benefits totaled $21,000, including estimated interest and penalties, as of December 31, 2014, 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. Additionally, the Company may be subject to insurance related claims resulting from matters associated with CoolSculpting treatments. 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 consolidated financial statements.
	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 has not accrued any amounts for these obligations.
	Severance and Separation Agreements
	Effective December 3, 2013, the Company's Chief Scientific Officer and Senior Vice President of Clinical entered into a separation agreement with the Company. As a result of this separation agreement, the Company incurred $0.3 million in termination benefits and $0.7 million in costs related to the modification of the employee's stock-based compensation, which were recorded during the year ended December 31, 2013. As of December 31, 2014, all of the termination benefits incurred during December 31, 2013 had been paid.
	Effective April 3, 2012, the Company's Vice President of North American Sales resigned from the Company. On April 18, 2012, the Company's President and CEO resigned from the positions he held with the Company. As a result of these resignations, the Company incurred $0.9 million in termination benefits and $0.7 million in costs related to the modification of the employees' stock-based compensation, which were recorded during the year ended December 31, 2012. Subsequent to these resignations, during the second quarter of 2012, the Company's management made a decision to terminate as well as accept resignations from several employees. As a result of these actions, the Company incurred approximately $0.8 million in termination benefits. As of December 31, 2013, all of the termination benefits incurred during December 31, 2012, had been paid.
	No similar costs were incurred during the year ended December 31, 2014.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity
	Preferred Stock
	The Company's Certificate of Incorporation, as amended in October 2011, authorizes the Company to issue 50,000,000 shares of preferred stock with a par value of $0.01 per share. In connection with the IPO, all of the Company's outstanding shares of convertible preferred stock were automatically converted into 24,415,965 shares of common stock. At December 31, 2014 and 2013, the Company had no preferred stock issued or outstanding.
	Common Stock
	Each share of common stock has the right to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the Board of Directors, subject to the prior rights of holders of all classes of stock outstanding having priority rights as to dividends. No dividends have been declared or paid as of December 31, 2014.

StockBased_Compensation_Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans
	2005 Stock Option Plan
	In 2005, the Company established its 2005 Stock Option Plan (the “2005 Plan”), which provided for the granting of stock options to employees and consultants of the Company. Options granted under the Plan were either incentive stock options (“ISOs”) or nonqualified stock options (“NSOs”). ISOs were granted only to Company employees (including officers and directors who are also employees). NSOs were granted to Company employees and consultants.
	Options under the Plan were granted for periods of up to ten years. The exercise price of an ISO and NSO should not be less than 100% and 85% of the estimated fair value of the shares on the date of grant, as determined by the Board of Directors. The exercise price of an ISO and NSO granted to a 10% stockholder should not be less than 110% of the estimated fair value of the shares on the date of grant, as determined by the Board of Directors. To date, options granted generally vested over four years at a rate of 25% upon the first anniversary of the issuance date and monthly thereafter. Cash received from employees for early exercise of unvested options was treated as a liability. Amounts so recorded were transferred into common stock and additional paid-in capital as the shares vested. The number of unvested shares and the associated liability amounts were immaterial at all reporting dates presented. As of December 31, 2014, no shares of the Company's common stock remained available for issuance under the 2005 Plan as a result of the adoption of the 2011 Equity Incentive Plan (the "2011 Plan").
	2011 Equity Incentive Plan
	In September 2011, the Company's Board of Directors approved the 2011 Plan that became effective upon the completion of the IPO.
	The 2011 Plan serves as the successor equity incentive plan to the Company's 2005 Plan and started with 89,234 shares of common stock available for issuance plus any shares of common stock issued pursuant to the 2005 Plan or subject to awards granted under the 2005 Plan that are forfeited, repurchased, returned or otherwise become available for issuance in accordance with the terms of the 2005 Plan. In addition, this plan reserve automatically increases on January 1 and each subsequent anniversary through January 1, 2021, by an amount equal to the smaller of five percent of the number of shares of common stock issued and outstanding on the immediately preceding December 31, or an amount determined by the Company's Board of Directors. The 2011 Plan provides for granting awards in the form of options, stock appreciation rights, restricted stock purchase rights, restricted stock bonuses, restricted stock units, performance shares, performance units, cash-based awards and other stock-based awards. Options granted under the 2011 Plan may be either ISOs or NSOs. ISOs may be granted only to the Company's employees. Any person who is not an employee of the Company on the effective date of the grant of an option may be granted only a NSO. Options under the 2011 Plan may be granted for periods of up to ten years and generally vest over a period of four years. The exercise price of an ISO and NSO shall not be less than 100% of the fair value of the shares on the date of grant. The exercise price of an ISO granted to a 10% stockholder shall not be less than 110% of the fair value of the underlying stock on the date of grant.
	2012 Stock Plan
	In April 2012, the Company's Board of Directors approved the 2012 Stock Plan ("2012 Plan") that became effective upon approval by the stockholders of the Company on June 15, 2012. The purpose of the 2012 Plan is to advance the interests of the Company and its stockholders by providing an incentive to attract, retain and reward persons performing services for the Company and by motivating such persons to contribute to the growth and profitability of the Company. The 2012 Plan seeks to achieve this purpose by providing for awards in the form of options, stock appreciation rights, restricted stock purchase rights, restricted stock bonuses, restricted stock units, performance shares, performance units, cash-based awards, other stock-based awards, and deferred compensation awards.
	The 2012 Plan started with 1,500,000 shares of common stock available for issuance and there are no provisions in the 2012 Plan to increase the shares available for issuance. Options granted under the 2012 Plan may be either ISOs or NSOs. ISOs may be granted only to the Company's employees. Any person who is not an employee of the Company on the effective date of the grant of an option may be granted only a NSO. Options under the 2012 Plan may be granted for periods of up to ten years and generally vest over a period of four years. The exercise price of an ISO and NSO shall not be less than 100% of the fair value of the shares on the date of grant. The exercise price of an ISO granted to a 10% stockholder shall not be less than 110% of the fair value of the underlying stock on the date of grant.
	Stock-based Compensation Activity
	Activity under the Company’s stock-based compensation plans is set forth below:
					Options Outstanding
		Shares			Number of			Weighted-				Weighted-Average Remaining Contractual Life (in Years)	Aggregate Intrinsic Value
		Available			Shares			Average
		for Grant						Exercise
								Price
													(in thousands)
	Balance, December 31, 2012	1,103,836			4,128,334			$	4.96
	Additional shares reserved	1,200,000			—			—
	Options granted	(568,987	)		568,987			6.6
	Restricted stock units granted	(1,205,200	)		—			—
	Options exercised	—			(791,198	)		3.34
	Options canceled	307,738			(307,738	)		7.36
	Restricted stock units canceled	163,689			—			—
	Restricted stock units withheld for tax	85,661			—			—
	Balance, December 31, 2013	1,086,737			3,598,385			$	5.36
	Additional shares reserved	1,851,794			—			—
	Options granted	(255,000	)		255,000			18.42
	Restricted stock units granted	(508,729	)		—			—
	Options exercised	—			(569,283	)		4.89
	Options canceled	41,681			(41,681	)		5.5
	Restricted stock units canceled	157,358			—			—
	Restricted stock units withheld for tax	311,368			—			—
	Balance, December 31, 2014	2,685,209			3,242,421			$	6.47			7.57	$	69,509
	Vested and expected to vest, December 31, 2014				3,121,593			$	6.47			7.56	$	66,927
	Exercisable, December 31, 2014				1,991,577			$	5.88			7.31	$	43,865
	The following table summarizes information about stock options outstanding as of December 31, 2014:
		Options Outstanding
	Exercise Price	Stock Options Outstanding			Weighted-Average Remaining Contractual Life (in Years)			Options Exercisable
	$0.55-4.00	358,312			5.5			277,565
	4.10-4.62	313,125			7.9			123,127
	5.04-5.04	1,431,102			7.6			923,059
	5.06-6.34	407,384			8			279,401
	6.38-10.20	396,448			7.3			256,242
	11.30-17.33	81,050			8			27,183
	17.44-17.44	5,000			9.2			—
	17.48-17.48	180,000			9.4			105,000
	20.88-20.88	50,000			9.1			—
	$21.00-21.00	20,000			9.2			—
		3,242,421						1,991,577
	Restricted Stock Activity
	Activity related to restricted stock units and awards is set forth below:
			Number of Units and Awards			Weighted-
						Average
						Grant Date Fair Value
	Balance, December 31, 2012		1,157,450			$	5.38
	Restricted stock units granted		1,205,200			5.57
	Restricted stock units released		(292,265	)		5.35
	Restricted stock units canceled		(163,689	)		4.31
	Balance, December 31, 2013		1,906,696			$	5.6
	Restricted stock units granted		508,729			19.99
	Restricted stock units released		(724,986	)		6.03
	Restricted stock units canceled		(157,358	)		6.5
Balance, December 31, 2014		1,533,081			$	10.08
During the year ended December 31, 2014, 724,986 shares vested subject to previously granted restricted stock units. A majority of these vested restricted stock units were net share settled. During the year ended December 31, 2014, the Company withheld 311,368 shares 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 year ended December 31, 2013, 292,265 shares vested subject to previously granted restricted stock units. During the year ended December 31, 2013, the Company withheld 85,661 shares 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.
2011 Employee Stock Purchase Plan
In September 2011, the Company's Board of Directors approved the 2011 Employee Stock Purchase Plan (“2011 ESPP”) that became effective upon the completion of the IPO. The 2011 ESPP is designed to enable eligible employees to purchase shares of the Company's common stock at a discount. Each offering period consists of one six-month purchase period. The purchase price for shares of common stock under the 2011 ESPP is 85% of the of lesser of the fair market value of the Company's common stock on the first day of the applicable offering period or the purchase date.
There were 470,018 shares of the Company's common stock initially reserved for future purchase under its 2011 ESPP. On the first day of each year, beginning January 1, 2012 and through and including January 1, 2021, the maximum aggregate number of shares of common stock that may be issued under the 2011 ESPP will be increased by a number of shares equal to the smallest of a) one percent of the number of shares of common stock issued and outstanding on the immediately preceding December 31, or b) an amount determined by the Company's Board of Directors. During 2013, the number of shares of the Company's common stock reserved for future purchase under the 2011 ESPP was increased by 150,000 shares. Additionally, during 2014, the number of shares of the Company's common stock reserved for future purchase under the 2011 ESPP was increased by 370,358 shares.
The initial offering period commenced on October 19, 2011, and ended on May 31, 2012. The future offering periods will commence on or about the first trading days of December and June of each year and end on or about the last trading days of the next May and November, respectively.
During the year ended December 31, 2014, employees purchased 103,089 shares under the 2011 ESPP at a weighted average exercise price of $14.86. As of December 31, 2014, there were 565,387 shares of the Company's common stock available for future purchase under its 2011 ESPP.
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 allocated as follows (in thousands):
	Year Ended December 31,
	2014				2013				2012
Revenue	$	833			$	—			$	—
Cost of revenue	443				248				131
Research and development	1,073				1,645				894
Sales and marketing	2,917				1,783				827
General and administrative	4,117				2,984				3,137
Total stock-based compensation	$	9,383			$	6,660			$	4,989
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 performance based stock options and restricted stock units was $1.6 million, $1.0 million and $0.3 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Stock-based compensation expense for both the years ended December 31, 2013 and 2012, includes $0.7 million in modification charges incurred in connection with the severance packages to the Company's former executives. There were no such charges for the year ended December 31, 2014.
Stock-based compensation for the year ended December 31, 2014, includes $0.8 million recorded as a reduction to revenue related to payments to customers for services. Of the total amount recorded as a reduction to revenue, $0.4 million is related to an out of period adjustment from the fiscal year ending December 31, 2013.
As of December 31, 2014, the total unrecognized compensation cost related to outstanding stock options, awards and employee stock purchases was $15.1 million, which will recognized using the straight-line attribution method over 2.2 years.
Stock-Based Compensation Associated with Awards to Employees
The Company uses the Black-Scholes option pricing model to determine the fair value of stock options. The valuation model for stock 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. The fair value of employee stock options was estimated using the following weighted-average assumptions:
	Year Ended December 31,
	2014			2013			2012
Expected term (in years)	4.4			4.8			5.2
Expected volatility	43	%		51	%		61	%
Risk-free interest rate	1.25	%		1.02	%		0.76	%
Expected dividend yield	0	%		0	%		0	%
Fair Value of Common Stock. The fair value of the underlying common stock was determined by the Board of Directors until the IPO when the Company's common stock started trading on the NASDAQ Global Select Market under ticker symbol ZLTQ on October 19, 2011. Consequently, after the IPO the fair value of the shares of common stock underlying the stock options is the closing price on the option grant date. Prior to the IPO, the fair value of the shares of common stock underlying the stock options was determined by the Board of Directors. Because there was no public market for the Company's common stock, the Board of Directors determined fair value of the common stock at the time of grant of the option by considering a number of objective and subjective factors including valuation of comparable companies, sales of convertible preferred stock to unrelated third parties, operating and financial performance, the lack of liquidity of capital stock, and general and industry specific economic outlook, amongst other factors.
Expected Term. Prior to the 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, the expected term used was based on expected term of a group of similar entities, referred to as “guideline” companies. In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size.
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 “guideline” companies. In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size. Subsequent to the IPO, the Company has continued to estimate its volatility based on this group of similar entities as the Company does not have sufficient historical data regarding its specific volatility.
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 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.
During the years ended December 31, 2014, 2013 and 2012, the Company granted 250,000; 543,987 and 2,860,927 stock options, respectively, to employees with a weighted-average grant date fair value of $6.77, $6.75, and $3.07 per share, respectively. The aggregate intrinsic value of options exercised was $3.2 million, $6.8 million and $6.0 million for the years ended December 31, 2014, 2013, and 2012, respectively. The aggregate intrinsic value is calculated as the difference between the exercise price and the estimated fair value of the Company's common stock at the date of exercise. The total fair value of shares vested was $4.3 million, $4.9 million and $2.1 million for the years ended December 31, 2014, 2013 and 2012, respectively.
During the years ended December 31, 2014, 2013 and 2012, the Company granted 508,729; 1,180,200 and 1,412,066 restricted stock units and restricted awards, respectively, to employees. The weighted-average grant date fair value as of the respective grant date of restricted stock units and restricted stock awards was $19.99, $5.62 and $5.70 for the years ended December 31, 2014, 2013 and 2012, respectively. There were no such awards granted for the year ended December 31, 2012. The fair value as of the respective vesting dates of restricted stock units and restricted stock awards was $4.3 million and $1.4 million and $0.3 million for the years ended December 31, 2014, 2013 and 2012, respectively.
There was no capitalized stock-based compensation cost during the years ended December 31, 2014, 2013 and 2012. The Company recognized stock-based compensation tax benefits of $87,000 during the year ended December 31, 2014. There was no recognized stock-based compensation tax benefits during the years ended December 31, 2013 and 2012.
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 each of the years ended December 31, 2014, 2013 and 2012, the Company granted stock-based awards to non-employees which vest over 0.5 to 2.0 years. Stock-based compensation expense related to non-employee grants was $0.6 million, $0.5 million and $0.8 million for the years ended December 31, 2014, 2013 and 2012, respectively, of which $0.8 million for an arrangement with a non-employee customer has been recorded as a reduction of revenue in the statement of operations during the year ended December 31, 2014. Included in this amount is $0.4 million of expense related to the year ended December 31, 2013.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	Employee Benefit Plans
	In 2005, the Company adopted a retirement savings plan under Section 401(k) of the Internal Revenue Code. This plan covers all employees in the United States who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. Company contributions to the plan may be made at the discretion of the Board of Directors. Matching 401(k) contributions expensed were $1.5 million, $1.1 million, and $0.7 million for the years ended December 31, 2014, 2013, and 2012, respectively.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	The domestic and foreign components of income (loss) before income taxes were as follows (in thousands):
		Year Ended December 31,
		2014				2013				2012
	Domestic income (loss)	$	1,443			$	(19,535	)		$	(30,329	)
	Foreign income (loss)	319				370				327
	Income (loss) before income taxes	$	1,762			$	(19,165	)		$	(30,002	)
	The income tax expense consisted of the following (in thousands):
		As of December 31,
		2014				2013				2012
	Current provision:
	Federal	$	—			$	—			$	—
	State	156				60				37
	Foreign	94				61				170
	Total current	250				121				207
	Deferred provision (benefit):
	Federal	—				—				—
	State	—				—				—
	Foreign	(19		)		19				(66		)
	Total deferred	(19		)		19				(66		)
	Total provision	$	231			$	140			$	141
	The following is a reconciliation of the statutory federal income tax rate to the Company's effective tax:
		Year Ended December 31,
		2014			2013			2012
	Tax at federal statutory rate	35	%		35	%		35	%
	State income taxes, net of federal benefit	6			2			(1	)
	Non-deductible permanent difference	22			(1	)		—
	Non-deductible executive compensation	150			—			—
	Change in valuation allowance	(157	)		(34	)		(34	)
	Research & development credits	(47	)		(2	)		1
	Stock-based compensation	6			(1	)		(1	)
	Impact of foreign operations	(2	)		—			—
	Effective tax rate	13	%		(1	)%		—	%
	Tax effects of temporary differences that give rise to significant portions of the deferred tax assets are presented below (in thousands):
		December 31,
		2014				2013
	Net operating loss carryforwards	$	31,237			$	45,401
	Income tax credits	4,838				2,379
	Depreciation & amortization	5,615				585
	Accruals & reserves	4,316				1,068
	Stock-based compensation	2,790				1,617
	Total deferred tax assets	48,796				51,050
	Valuation allowance	(48,730		)		(51,003		)
	Net deferred tax assets	$	66			$	47
	As of December 31, 2014, the Company had federal and state net operating loss carryforwards of $109.2 million and $97.9 million, respectively. Unrecognized deferred tax benefits of approximately $32.6 million resulting from the exercises of employee stock awards will be accounted for as a credit to additional paid-in capital if and when realized through a reduction in the income tax payable. The federal net operating losses begin expiring in 2025 and state net operating losses begin expiring in 2015. As of December 31, 2014, the Company had credit carryforwards of approximately $3.4 million and $3.8 million available to reduce future taxable income, if any, for federal and state income tax purposes, respectively. The federal research and development credit carryforwards expire beginning 2025, and state credits can be carried forward indefinitely.
	Management believes that, based on a number of factors, which includes the Company’s historical operating performance and accumulated deficit, it is more likely than not that the U.S. deferred tax assets will not be utilized, such that a full valuation allowance has been recorded against the Company's U.S. deferred tax assets. Valuation allowance increased (decreased) by approximately $(2.3) million, and $6.1 million for the years ended December 31, 2014 and 2013, respectively. Management believes that, based on a number of factors, it is more likely than not that the United Kingdom deferred tax assets will be utilized and accordingly there was no valuation allowance recorded to these deferred tax assets.
	The valuation allowance for deferred tax assets consisted of the following activity for the fiscal years ended December 31, 2014, 2013 and 2012 (in thousands):
	Description	Balance at Beginning of Year				Additions				Reductions			Balance at End of Year
	Year ended December 31, 2012	$	32,836			$	12,090			$	—		$	44,926
	Year ended December 31, 2013	44,926				6,077				—			51,003
	Year ended December 31, 2014	$	51,003			$	1,011			$	3,284		$	48,730
	The Company intends to continue maintaining 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, within the next year, 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. As such, the Company may release a significant portion, or all, of its valuation allowance against its deferred tax assets within the next 12 months. This release would result in the recognition of certain deferred tax assets and a decrease to income tax expense for the period such release is recorded.
	Utilization of net operating losses and tax credit carryforwards may be limited by ownership change rules, as defined in Section 382 of the Internal Revenue Code. Similar rules may apply under state tax laws. The Company has assessed the application of Internal Revenue Code Section 382, during the fourth quarter of 2014, and concluded no limitation currently applies, and the Company will continue to monitor activities in the future. In the event the Company experiences any subsequent changes in ownership, the amount of net operating losses and research and development credit carryovers available in any taxable year could be limited and may expire unutilized.
	On December 19, 2014, the President signed into law The Tax Increase Prevention Act of 2014, which retroactively extends more than 50 expired tax provisions through 2014. Among the extended provisions is the Section 41 research credit for qualified research expenditures incurred through the end of 2014. The benefit of the reinstated credit did not impact the income statement in the period of enactment, which was the fourth quarter of 2014, as the research and development credit carryforwards are offset by a full valuation allowance.
	During the year ended December 31, 2014, the amount of gross unrecognized tax benefits decreased by $1.5 million. The total amount of unrecognized tax benefits was $1.5 million as of December 31, 2014, of which $21,000, 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.
	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):
	Balance as of January 1, 2012	$	824
	Gross increase (decrease) on tax positions related to the current year	78
	Balance as of December 31, 2012	902
	Gross increase (decrease) on tax positions related to the prior year	1,434
	Gross increase (decrease) on tax positions related to the current year	589
	Balance as of December 31, 2013	2,925
	Gross increase (decrease) on tax positions related to the prior year	(1,746		)
	Gross increase (decrease) on tax positions related to the current year	274
Balance as of December 31, 2014	$	1,453
The Company files income tax returns in the U.S. federal and state jurisdictions, in the United Kingdom and Ireland and all returns since inception remain open to examination.

Net_Income_Loss_per_Share_of_C

Net Income (Loss) per Share of Common Stock	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Net Income (Loss) per Share of Common Stock	Net Income (Loss) per Share of Common Stock
	Basic net income (loss) per share of common stock 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 of common stock 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:
		Year Ended December 31,
		2014			2013			2012
	Numerator
	Net income (loss) (in thousands)	1,531			(19,305		)	(30,143		)
	Denominator
	Weighted average shares of common stock outstanding used in computing net income (loss) per share, basic	37,563,590			36,209,051			34,776,380
	Dilutive effect of incremental shares and share equivalents	3,433,382			—			—
	Weighted average shares of common stock outstanding used in computing net income (loss) per share, diluted	40,996,972			36,209,051			34,776,380
	Net income (loss) per share:
	Net income (loss) per share, basic	$	0.04		$	(0.53	)	$	(0.87	)
	Net income (loss) per share, diluted	$	0.04		$	(0.53	)	$	(0.87	)
	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:
		Year Ended
		December 31,
		2014		2013			2012
	Options to purchase common stock	220,712		3,598,385			4,128,334
	Restricted stock units	12,723		1,906,696			119,507
	Common stock issuable pursuant to the ESPP	—		86,026			21,586
	Total	233,435		5,591,107			4,269,427

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information
	The supplemental cash flow information consists of the following (in thousands):
		Year Ended
		December 31,
		2014			2013			2012
	Cash paid for interest	$	—		$	—		$	2
	Cash paid for income taxes	$	285		$	188		$	47
	Non-cash investing and financing activities:
	Assets acquired under capital leases	$	(382	)	$	—		$	—
	Changes in accounts payable and accrued liabilities related to property, plant and equipment purchases	$	91		$	(33	)	$	(100	)

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
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):
		Year Ended
		December 31,
		2014		2013		2012
	North America	$	134,434	$	89,150	$	56,657
	International	40,044		22,476		19,537
	Total	$	174,478	$	111,626	$	76,194
	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 $125.0 million, $83.7 million and $54.7 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	The following table sets forth revenue by product expressed as dollar amounts (in thousands):
		Year Ended
		December 31,
		2014		2013		2012
	System revenue	$	93,015	$	61,359	$	39,145
	Consumable revenue	81,463		50,267		37,049
	Total	$	174,478	$	111,626	$	76,194
	Substantially all of the Company’s long-lived assets are located in the United States of America.

Selected_Quarterly_Financial_D

Selected Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (unaudited)	Selected Quarterly Financial Data (unaudited)
	The following table presents selected unaudited consolidated financial data for each of the eight quarters in the two-year period ended December 31, 2014. The selected quarterly financial data should be read in conjunction with the Company's consolidated financial statements and the related notes and "Item 7: Management's Discussion and Analysis of Financial Condition and Results of Operations". This information has been derived from the Company's unaudited consolidated financial statements that, in management's opinion, reflect all recurring adjustments necessary to fairly state this information when read in conjunction with the Company's consolidated financial statements and the related notes appearing in the section entitled "Consolidated Financial Statements". Net income (loss) per share-basic and diluted, for the four quarters of each fiscal year may not sum to the total for the fiscal year because of the different number of shares outstanding during each period. The results of operations for any quarter are not necessarily indicative of the results to be expected for any future period.
		Quarter
		First			Second			Third			Fourth
		(In thousands, except share and per share data)
	Year Ended December 31, 2014
	Total revenue	$	30,975		$	47,061		$	45,670		$	50,772
	Gross profit	$	21,959		$	33,401		$	33,115		$	35,939
	Net income (loss)	$	(7,337	)	$	2,769		$	4,782		$	1,317
	Net income (loss) per share, basic	$	(0.20	)	$	0.07		$	0.13		$	0.03
	Shares used in calculation-basic	37,215,697			37,440,537			37,630,222			37,958,395
	Net income (loss) per share, diluted	$	(0.20	)	$	0.07		$	0.12		$	0.03
	Shares used in calculation-diluted	37,215,697			40,597,275			40,926,034			41,434,178
	Year Ended December 31, 2013
	Total revenue	$	19,982		$	26,338		$	29,465		$	35,841
	Gross profit	$	12,634		$	18,460		$	21,229		$	25,114
	Net income (loss)	$	(7,482	)	$	(3,607	)	$	(2,811	)	$	(5,405	)
	Net income (loss) per share, basic and diluted	$	(0.21	)	$	(0.10	)	$	(0.08	)	$	(0.15	)
	Shares used in calculation-basic and diluted	35,890,084			36,045,346			36,206,008			36,686,053

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP.
Principles of Consolidation	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.
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.
Significant Risks and Uncertainties	Significant Risks and Uncertainties
	The Company's future results of operations involve a number of risks and uncertainties. Factors that could affect the Company's future operating results and cause actual results to vary materially from expectations include, but are not limited to, rapid technological change, continued acceptance of the Company's products, competition from substitute products and larger companies, ability to protect proprietary technology from copy-cat or counterfeit versions the Company's products, strategic relationships and dependence on key individuals. If the Company fails to adhere to ongoing Food and Drug Administration, or FDA, Quality System Regulation, the FDA may withdraw its market clearance or take other action. The Company relies on sole-source suppliers to manufacture some of the components used in its product. The Company's manufacturers and suppliers may encounter supply interruptions or problems during manufacturing due to a variety of reasons, including failure to comply with applicable regulations, including the FDA's Quality System Regulation, equipment malfunction and environmental factors, any of which could delay or impede the Company's ability to meet demand.
Concentration of Credit Risk	Concentration of Credit Risk
	Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash equivalents, marketable securities and trade receivables. The Company's cash equivalents and marketable securities are held in safekeeping by large, credit worthy financial institutions. The Company invests its excess cash primarily in U.S. banks, government and agency bonds, money market funds and corporate obligations. The Company has established guidelines relative to credit ratings, diversification and maturities that seek to maintain safety and liquidity. Deposits in these banks may exceed the amounts of insurance provided on such deposits. To date, the Company has not experienced any losses on its deposits of cash and cash equivalents.
	The Company controls credit risk through credit approvals, credit limits, and monitoring procedures. The Company performs periodic credit evaluations of its customers and generally does not require collateral. Accounts receivable are recorded net of an allowance for doubtful accounts. The allowance for doubtful accounts is based on management's assessment of the collectability of specific customer accounts and the aging of the related invoices, and represents the Company's best estimate of probable credit losses in its existing trade accounts receivable.
Cash and Cash Equivalents	Cash and Cash Equivalents
	The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents.
Investments	Investments
	The Company invests its excess cash balances primarily in certificates of deposit, commercial paper, corporate bonds, and U.S. Government agency securities. Investments with original maturities greater than 90 days that mature less than one year from the consolidated balance sheet date are classified as short-term investments. The Company classifies all of its investments as available-for-sale and records such assets at estimated fair value in the consolidated balance sheets, with unrealized gains and losses, if any, reported as a component of accumulated other comprehensive income (loss) in stockholders' equity. Realized gains and losses from maturities of all such securities are reported in earnings and computed using the specific identification cost method.  Realized gains or losses and charges for other-than-temporary declines in value, if any, on available-for-sale securities are reported in other income (expense), net as incurred.  The Company periodically evaluates these investments for other-than-temporary impairment.
Inventory	Inventory
	Inventory is stated at the lower of cost (which approximates actual cost on a first-in, first-out basis) or market, computed on a standard cost basis. 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 and market conditions. Inventory write-downs are charged to cost of revenue and establish a new cost basis for the inventory.
Property and Equipment	Property and Equipment
	Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Maintenance and repairs are charged to expense as incurred. Assets not yet placed in use are not depreciated.
	The useful lives of the property and equipment are as follows:
	Lab equipment, tooling, and molds	5 years
	Computer equipment	3 years
	Computer software	3 years
	Furniture and fixtures	5 years
	Vehicles	5 years
	Leasehold improvements	Shorter of lease term or estimated useful life
Capitalized Software	Capitalized Software
	The Company capitalizes costs associated with customized internal-use software systems that have reached the application development stage and meet recoverability tests. Such capitalized costs mainly include external direct costs utilized in developing or obtaining the applications. Capitalization of such costs begins when the preliminary project stage is complete and ceases at the point in which the project is substantially complete and is ready for its intended purpose. The capitalized costs associated with internal-use software are depreciated on a straight-line basis over each asset's estimated useful life, which is generally three years.
Intangible Asset	Intangible Asset
	The intangible asset consists of an exclusive license agreement for commercializing patents and other technology. All milestone payments subsequent to the date of the FDA approval are 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.
Impairment of Long-Lived Assets	Impairment of Long-lived Assets
	The Company reviews property and equipment and the intangible asset for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future undiscounted net cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the assets' fair value determined using the projected discounted future net cash flows arising from the asset.
Revenue Recognition	Revenue Recognition
	The Company’s revenue is derived from the sales of the CoolSculpting system, consisting of a control unit and applicators, and, from time to time, related extended warranty arrangements, and from the sale of cycles in the form of consumable procedure packs, each of which includes consumable CoolGels, CoolLiners, and in the case of the Company's CoolSmooth procedure packs, disposable securement accessories, all of which are used by the Company's customer during treatments. In addition, each consumable procedure pack includes a disposable computer cartridge that the Company markets as the CoolCard. The CoolCard contains enabling software that permits the Company's customers to perform a fixed number of CoolSculpting procedures, or cycles. This software is not marketed separately from the CoolSculpting system or from the CoolCard. Rather, the functionality that the software provides is part of the overall CoolCard product. The CoolSculpting system is marketed as a non-invasive aesthetic device for the selective reduction of fat, not for its embedded software attributes included in the CoolCard that enable its use. The Company does not provide rights to upgrades and enhancements or post-contract customer support for the embedded software. In addition, the Company does not incur significant software development costs or capitalize its software development costs. Based on this assessment, the Company considers the embedded software in the CoolCard incidental to the CoolCard product as a whole and determined that revenue recognition should not be governed by the provisions of Topic 985 of the FASB Accounting Standards Codification, or ASC. The Company earns revenue from the sale of its products to its customers and to distributors. The Company recognizes revenue when persuasive evidence of an arrangement exists, transfer of title to the customer has occurred, the sales price is fixed or determinable, and collectability is probable. Revenue is deferred in the event that any of the revenue recognition criteria is not met.
	Persuasive Evidence of an Arrangement. The Company uses contracts or customer purchase orders to determine the existence of an arrangement.
	Transfer of title. The Company's standard terms specify that title transfers upon shipment to the customer. The Company uses third party shipping documents to verify that title has transferred.
	Sales Price Fixed or Determinable. The Company assesses whether the sales price is fixed or determinable at the time of the transaction. Sales prices are documented in the executed sales contract or purchase order received prior to shipment. The Company’s standard terms do not allow for trial or evaluation periods, rights of return or refund, payments contingent upon the customer obtaining financing or other terms that could impact the customer’s obligation.
	Collectability. The Company assesses whether collection is reasonably assured based on a number of factors, including the customer’s past transaction history and credit worthiness.
	Multiple-Element Arrangements. Typically, all products sold to a customer are delivered at the same time. If a partial delivery occurs as authorized by the customer, the Company allocates revenue to the various products based on their vendor-specific objective evidence of fair value, or VSOE, if VSOE exists according to ASC 605-25 as the basis of determining the relative selling price of each element. If VSOE does not exist, the Company may use third party evidence of fair value, or TPE, to determine the relative selling price of each element. If neither VSOE nor TPE exists, the Company may use management’s best estimate of the sales price, or ESP, of each element to determine the relative selling price. The relative selling prices for control units, applicators, CoolCards and extended warranty are based on established price lists and separate, stand-alone sales of these elements. The Company establishes best estimates within a range of selling prices considering multiple factors including, but not limited to, factors such as size of transaction, pricing strategies and market conditions. The Company believes the use of the ESP allows revenue recognition in a manner consistent with the underlying economics of the transaction. The Company’s products do not require maintenance or support. In a multiple-element arrangement, revenue is deferred for undelivered elements, which are generally training or extended warranty. Revenue on undelivered elements of an arrangement is recognized when all revenue recognition criteria have been met.
Customer Programs and Payments	Customer Programs and Payments
	Accruals for Customer Programs
	The Company records an accrued liability for cooperative marketing arrangements and customer incentive programs. The estimated cost of these programs is recorded as a reduction of revenue or as an operating expense, if the Company receives a separately identifiable benefit from the customer and can reasonably estimate the fair value of that benefit. Significant management judgment and estimates must be used to determine the cost of these programs in any accounting period.
	Cooperative Marketing Arrangements.  The Company offers cooperative marketing programs to its North American customers, allowing the customer to receive partial reimbursement for qualifying advertising expenditures which promote the Company's product and brand. Customer participation, as well as reimbursement amounts, is predicated upon purchase levels of CoolCards. The objective of these arrangements is to encourage advertising and promotional events to increase sales of the Company's products. Accruals for these marketing arrangements are recorded at the time of sale, or time of commitment, based on the related program parameters, review of related advertising and historical experience.
	Customer Incentive Programs. The Company's customer incentive program consists of rebates for its North American customers based on purchase levels of CoolCards. Estimated costs of consumer rebates and similar incentives are recorded at the time the incentive is offered, based on the specific terms and conditions of the program.
	Accounting for Payments to Customers
	The Company occasionally enters into transactions where it provides consideration to its customers in the forms of cash payments or stock-based awards in exchange for certain goods and services. The Company accounts for such payments to customers in accordance with ASC 605-50, Revenue Recognition: Customer Payments and Incentives, which requires the Company to characterize the payment as a reduction of revenue if the Company is unable to demonstrate the receipt of a benefit that is identifiable and sufficiently separable from the revenue transaction and reasonably estimate the fair value of the benefit identified. Significant management judgment and estimates must be used to determine the fair value of the benefit received in any period. For stock awards, the Company believes that the fair value of the awards is more reliably measured than the fair value of the benefit received. The fair value of the stock awards is measured as of the date at which either the commitment for performance by the customer to earn the award is reached or the date the customer’s performance is complete. Until that point is reached, the award is revalued at each reporting period with the true-up to fair value recorded in current period earnings.
Cost of Revenues	Cost of Revenue
	Cost of revenue consists primarily of cost of finished and semi-finished products purchased from the Company's third-party suppliers, labor, material, and overhead involved in its internal manufacturing processes, technology amortization and royalty fees and cost of product warranty. In the event that a revenue transaction is deferred, the corresponding cost associated with the transaction will also be deferred.
Shipping and Handling	Shipping and Handling
	Shipping and handling costs charged to customers are recorded as revenue. Shipping costs are included in cost of revenue.
Research and Development	Research and Development
	Research and development costs primarily consist of salaries, benefits, incentive compensation, stock-based compensation, and allocated facilities costs for employees and contractors engaged in research, clinical studies, regulatory affairs, and development. The Company expenses all research and development costs in the periods in which they are incurred.
Advertising Costs	Advertising costs
	The cost of advertising and media is expensed as incurred.
Product Warranty	Product Warranty
	The Company provides a standard limited warranty on its products of 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 approximately three years for control units and one year for applicators.
	The Company accrues for the estimated future costs of repair or replacement upon shipment. The warranty accrual is 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 Company offers an extended warranty on both its CoolSculpting control units and CoolSculpting applicators. The Company recognizes the revenue from the sale of an extended warranty over the extended warranty coverage period. The Company's revenue and related obligations from sale of extended warranties to date has not been significant.
Stock-Based Compensation	Stock-Based Compensation
	The Company maintains incentive plans under which incentive and nonqualified stock options are granted primarily to employees and non-employee consultants.
	Stock-based compensation cost is measured at the grant date, based on the fair value of the award, and is recognized as expense on a straight-line basis over the requisite service period. The fair value of stock-based awards to employees is estimated using the Black-Scholes option pricing model. The Company estimates its forfeiture rate based on an analysis of its actual forfeitures and will continue to evaluate the adequacy of the forfeiture rate assumption based on actual forfeitures, analysis of employee turnover, and other related factors.
	Stock-based compensation expense related to stock options granted to non-employees is recognized as the stock options are earned. The awards generally vest ratably over the time period the Company expects to receive services from the non-employee. The fair values attributable to these options are amortized over the service period and the unvested portion of these options is remeasured at each vesting date.
Income Taxes	Income Taxes
	The Company utilizes the asset and liability method of accounting for income taxes, under which deferred taxes are determined based on the temporary differences between the financial statement and tax basis of assets and liabilities using tax rates expected to be in effect during the years in which the basis differences reverse and for operating losses and tax credit carryforwards. The Company estimates its income taxes and amounts ultimately payable or recoverable in multiple tax jurisdictions around the world. Estimates involve interpretations of regulations and are inherently complex. Resolution of income tax treatments in individual jurisdictions may not be known for many years after completion of any fiscal year. The Company is required to evaluate the realizability of its deferred tax assets on an ongoing basis to determine whether there is a need for a valuation allowance with respect to such deferred tax assets. A valuation allowance is recorded when it is more likely than not that some or all of the deferred tax assets will not be realized. Significant management judgment is required in determining any valuation allowance recorded against deferred tax assets. In evaluating the ability to recover deferred tax assets, the Company considers all available positive and negative evidence giving greater weight to its recent cumulative losses and its ability to carryback losses against prior taxable income and, commensurate with objective verifiability, the forecast of future taxable income including the reversal of temporary differences and the implementation of feasible and prudent tax planning strategies.
	The Company recognizes and measures uncertain tax positions taken or expected to be taken in a tax return if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such positions are then measured based on the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate settlement. The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in a tax return. The Company adjusts these reserves in light of changing facts and circumstances, such as the closing of a tax audit or the refinement of an estimate. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will impact the provision for income taxes in the period in which such determination is made. The provision for income taxes includes the impact of reserve provisions and changes to reserves that are considered appropriate, as well as the related net interest. The Company recognizes interest and penalties related to unrecognized tax benefits within the income tax provision. Accrued interest and penalties are included within the related tax liability line in the consolidated balance sheet.
	The Company files annual income tax returns in multiple taxing jurisdictions around the world. 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.
Net Income (Loss) Per Share	Net Income (Loss) Per Share
	Basic net income (loss) per share of common stock 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 of common stock is computed by giving effect to all potentially dilutive securities outstanding during the period, including options, restricted stock units and common stock issuable pursuant to the ESPP.
Comprehensive Income (Loss)	Comprehensive Income (Loss)
	Accumulated other comprehensive income (loss) includes foreign currency translation adjustments and unrealized gains (losses) on available-for-sale securities net of tax, the impact of which has been excluded from earnings and reflected as components of stockholders' equity.
Foreign currency translation	Foreign currency translation
	Based on an evaluation of economic facts and circumstances together with the functional currency analysis prescribed in ASC 830, Foreign Currency Matters, on October 1, 2013, the Company changed the functional and reporting currency for its operations in the United Kingdom from the U.S. Dollar to the British Pound. Such change did not have a material impact on the consolidated financial statements of the Company. The functional and reporting currency is the Euro for the Company's operations in Ireland and the U.S. dollar for all of its other foreign operations.
	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.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	On May 28, 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update No. 2014-10, 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. The Company will adopt this guidance effective January 1, 2017, and is currently assessing the impact it may have on the Company's consolidated financial statements.
	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 will not have an impact on the Company's consolidated financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Allowance for Doubtful Accounts	The allowance for doubtful accounts consisted of the following activity for fiscal years ended December 31, 2014, 2013 and 2012 (in thousands):
	Description		Balance at Beginning of Year			Additions		Reductions		Balance at End of Year
	Year ended December 31, 2012		$	40		$	329	$	39	$	330
	Year ended December 31, 2013		330			59		389		—
	Year ended December 31, 2014		—			469		145		324
Useful Lives of Property and Equipment	The useful lives of the property and equipment are as follows:
	Lab equipment, tooling, and molds	5 years
	Computer equipment	3 years
	Computer software	3 years
	Furniture and fixtures	5 years
	Vehicles	5 years
	Leasehold improvements	Shorter of lease term or estimated useful life
	Property and equipment, net comprised the following (in thousands):
		December 31,
		2014			2013
	Lab equipment, tooling and molds	$	2,766		$	2,071
	Computer software	1,337			1,562
	Computer equipment	984			801
	Leasehold improvements	1,452			743
	Furniture and fixtures	494			334
	Vehicles	35			35
	Total property and equipment	7,068			5,546
	Less: Accumulated depreciation and amortization	(4,111		)	(3,594		)
	Construction in progress	767			206
	Property and equipment, net	$	3,724		$	2,158
Components of accumulated other comprehensive income	Components of accumulated other comprehensive income (loss) was as follows (in thousands):
		December 31,
		2014			2013
	Cumulative translation adjustments	$	(690	)	$	77
	Unrealized gain (loss) on marketable securities, net of tax	(6		)	10
	Accumulated other comprehensive income (loss)	$	(696	)	$	87

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
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 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
		As of December 31, 2013
		Level 1		Level 2		Level 3		Fair Value
	Financial Assets
	Cash equivalents:
	Money market funds	$	12,796	$	—	$	—	$	12,796
	Short-term investments:
	U.S. Agency securities	—		6,772		—		6,772
	U.S. Treasury	—		1,001		—		1,001
	Corporate bonds	—		8,870		—		8,870
	Commercial paper	—		999		—		999
	Certificates of deposit	1,198		—		—		1,198
	Long-term investments:
	U.S. Agency securities	—		6,956		—		6,956
	U.S. Treasury	—		1,014		—		1,014
	Corporate bonds	—		2,795		—		2,795
	Certificates of deposit	677		—		—		677
	Total	$	14,671	$	28,407	$	—	$	43,078

Balance_Sheet_Components_Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Investments	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
	The Company's short-term and long-term investments as of December 31, 2013, are as follows (in thousands):
	Short-term
		Amortized Cost			Gross Unrealized Gains			Gross Unrealized Losses			Fair Value
	U.S. Agency securities	$	6,771		$	2		$	(1	)	$	6,772
	U.S. Treasury	1,000			1			—			1,001
	Corporate bonds	8,867			3			—			8,870
	Commercial paper	999			—			—			999
	Certificates of deposit	1,198			—			—			1,198
	Total	$	18,835		$	6		$	(1	)	$	18,840
	Long-term
		Amortized Cost			Gross Unrealized Gains			Gross Unrealized Losses			Fair Value
	U.S. Agency securities	$	6,957		$	2		$	(3	)	$	6,956
	U.S. Treasury	1,013			1			—			1,014
	Corporate bonds	2,790			5			—			2,795
	Certificates of deposit	677			—			—			677
	Total	$	11,437		$	8		$	(3	)	$	11,442
Schedule of Contractual Maturities of Investments	The contractual maturities of the Company's short-term and long-term investments as of December 31, 2014, are as follows (in thousands):
		December 31, 2014
		Amortized Cost			Fair Value
	Due in one year or less	$	16,289		$	16,286
	Due in one year to five years	4,808			4,805
		$	21,097		$	21,091
Schedule of Inventory	The components of inventory consist of the following (in thousands):
		December 31,
		2014			2013
	Raw materials	$	7,692		$	4,520
	Finished goods	7,844			3,886
	Total inventory	$	15,536		$	8,406
Schedule of Property and Equipment	The useful lives of the property and equipment are as follows:
	Lab equipment, tooling, and molds	5 years
	Computer equipment	3 years
	Computer software	3 years
	Furniture and fixtures	5 years
	Vehicles	5 years
	Leasehold improvements	Shorter of lease term or estimated useful life
	Property and equipment, net comprised the following (in thousands):
		December 31,
		2014			2013
	Lab equipment, tooling and molds	$	2,766		$	2,071
	Computer software	1,337			1,562
	Computer equipment	984			801
	Leasehold improvements	1,452			743
	Furniture and fixtures	494			334
	Vehicles	35			35
	Total property and equipment	7,068			5,546
	Less: Accumulated depreciation and amortization	(4,111		)	(3,594		)
	Construction in progress	767			206
	Property and equipment, net	$	3,724		$	2,158
Schedule of Accrued Liabilities	The following table shows the components of accrued liabilities (in thousands):
		December 31,
		2014			2013
	Accrued payroll and employee related expenses	$	8,386		$	7,863
	Accrued marketing expenses	2,959			3,739
	Accrued royalty	3,612			2,458
	Sales and other taxes payable	2,123			1,787
	Advance payments from customers	1,908			1,216
	Accrued warranty	569			676
	Accrued legal expenses	592			284
	Other accrued liabilities	1,301			341
	Total accrued liabilities	$	21,450		$	18,364
Schedule of Product Warranty Accrual	The estimated product warranty accrual was as follows (in thousands):
		December 31,
		2014			2013
	Balance at the beginning of the period	$	676		$	902
	Accruals for warranties issued	284			197
	Settlements of warranty claims	(391		)	(423		)
	Balance at the end of the period	$	569		$	676

License_Agreement_With_Massach1

License Agreement With Massachusetts General Hospital (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	The intangible asset, net comprised the following (in thousands):
		December 31,			December 31,
		2014			2013
	Purchased technology	$	8,050		$	8,050
	Less: Accumulated amortization	(2,270		)	(1,569		)
	Intangible asset, net	$	5,780		$	6,481
Schedule of Estimated Future Amortization Expense of Intangible Assets	The total estimated annual future amortization expense of this intangible asset as of December 31, 2014, is as follows (in thousands):
	Fiscal Year
	2015	$	701
	2016	701
	2017	701
	2018	701
	2019	701
	Thereafter	2,275
	Total	$	5,780

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
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 December 31, 2014, are as follows (in thousands):
	Year Ending December 31,	Amount
	2015	$	1,844
	2016	1,591
	2017	1,624
	2018	1,666
	2019	507
	Thereafter	84
	Total future minimum lease payments	$	7,316
Schedule of Capital Leased Assets	Property and equipment includes the following amounts under leases that have been capitalized as of December 31, 2014, as follows (in thousands):
		Useful life (Years)		December 31,
				2014
	Computer equipment	3		382
	Total capital leased equipment			382
	Less: Accumulated depreciation and amortization			(21		)
	Capital leased equipment, net			$	361
Schedule of Future Minimum Lease Payments Required Under Capital Leases	Future minimum payments required under capital leases as of December 31, 2014, are as follows (in thousands):
	Year Ending December 31,	Amount
	2015	$	132
	2016	132
	2017	141
	Total future payments	$	405
	Less: Amount representing interest	$	23
	Present value of future minimum payments	382
	Less: Current portion	120
	Long term portion	$	262

StockBased_Compensation_Plans_

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation Activity	Activity under the Company’s stock-based compensation plans is set forth below:
					Options Outstanding
		Shares			Number of			Weighted-				Weighted-Average Remaining Contractual Life (in Years)	Aggregate Intrinsic Value
		Available			Shares			Average
		for Grant						Exercise
								Price
													(in thousands)
	Balance, December 31, 2012	1,103,836			4,128,334			$	4.96
	Additional shares reserved	1,200,000			—			—
	Options granted	(568,987	)		568,987			6.6
	Restricted stock units granted	(1,205,200	)		—			—
	Options exercised	—			(791,198	)		3.34
	Options canceled	307,738			(307,738	)		7.36
	Restricted stock units canceled	163,689			—			—
	Restricted stock units withheld for tax	85,661			—			—
	Balance, December 31, 2013	1,086,737			3,598,385			$	5.36
	Additional shares reserved	1,851,794			—			—
	Options granted	(255,000	)		255,000			18.42
	Restricted stock units granted	(508,729	)		—			—
	Options exercised	—			(569,283	)		4.89
	Options canceled	41,681			(41,681	)		5.5
	Restricted stock units canceled	157,358			—			—
	Restricted stock units withheld for tax	311,368			—			—
	Balance, December 31, 2014	2,685,209			3,242,421			$	6.47			7.57	$	69,509
	Vested and expected to vest, December 31, 2014				3,121,593			$	6.47			7.56	$	66,927
	Exercisable, December 31, 2014				1,991,577			$	5.88			7.31	$	43,865
Summary of Stock Options Outstanding by Exercise Price Range	The following table summarizes information about stock options outstanding as of December 31, 2014:
		Options Outstanding
	Exercise Price	Stock Options Outstanding			Weighted-Average Remaining Contractual Life (in Years)			Options Exercisable
	$0.55-4.00	358,312			5.5			277,565
	4.10-4.62	313,125			7.9			123,127
	5.04-5.04	1,431,102			7.6			923,059
	5.06-6.34	407,384			8			279,401
	6.38-10.20	396,448			7.3			256,242
	11.30-17.33	81,050			8			27,183
	17.44-17.44	5,000			9.2			—
	17.48-17.48	180,000			9.4			105,000
	20.88-20.88	50,000			9.1			—
	$21.00-21.00	20,000			9.2			—
		3,242,421						1,991,577
Restricted Stock Activity	Activity related to restricted stock units and awards is set forth below:
			Number of Units and Awards			Weighted-
						Average
						Grant Date Fair Value
	Balance, December 31, 2012		1,157,450			$	5.38
	Restricted stock units granted		1,205,200			5.57
	Restricted stock units released		(292,265	)		5.35
	Restricted stock units canceled		(163,689	)		4.31
	Balance, December 31, 2013		1,906,696			$	5.6
	Restricted stock units granted		508,729			19.99
	Restricted stock units released		(724,986	)		6.03
	Restricted stock units canceled		(157,358	)		6.5
	Balance, December 31, 2014		1,533,081			$	10.08
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 allocated as follows (in thousands):
		Year Ended December 31,
		2014				2013				2012
	Revenue	$	833			$	—			$	—
	Cost of revenue	443				248				131
	Research and development	1,073				1,645				894
	Sales and marketing	2,917				1,783				827
	General and administrative	4,117				2,984				3,137
	Total stock-based compensation	$	9,383			$	6,660			$	4,989
Summary of Fair Value of Employee Stock Option Assumptions	The fair value of employee stock options was estimated using the following weighted-average assumptions:
		Year Ended December 31,
		2014			2013			2012
	Expected term (in years)	4.4			4.8			5.2
	Expected volatility	43	%		51	%		61	%
	Risk-free interest rate	1.25	%		1.02	%		0.76	%
	Expected dividend yield	0	%		0	%		0	%

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of Domestic and Foreign Income (Loss) before Income Taxes	The domestic and foreign components of income (loss) before income taxes were as follows (in thousands):
		Year Ended December 31,
		2014				2013				2012
	Domestic income (loss)	$	1,443			$	(19,535	)		$	(30,329	)
	Foreign income (loss)	319				370				327
	Income (loss) before income taxes	$	1,762			$	(19,165	)		$	(30,002	)
Schedule of Components of Income Tax Expense	The income tax expense consisted of the following (in thousands):
		As of December 31,
		2014				2013				2012
	Current provision:
	Federal	$	—			$	—			$	—
	State	156				60				37
	Foreign	94				61				170
	Total current	250				121				207
	Deferred provision (benefit):
	Federal	—				—				—
	State	—				—				—
	Foreign	(19		)		19				(66		)
	Total deferred	(19		)		19				(66		)
	Total provision	$	231			$	140			$	141
Schedule of Effective Income Tax Rate Reconciliation	The following is a reconciliation of the statutory federal income tax rate to the Company's effective tax:
		Year Ended December 31,
		2014			2013			2012
	Tax at federal statutory rate	35	%		35	%		35	%
	State income taxes, net of federal benefit	6			2			(1	)
	Non-deductible permanent difference	22			(1	)		—
	Non-deductible executive compensation	150			—			—
	Change in valuation allowance	(157	)		(34	)		(34	)
	Research & development credits	(47	)		(2	)		1
	Stock-based compensation	6			(1	)		(1	)
	Impact of foreign operations	(2	)		—			—
	Effective tax rate	13	%		(1	)%		—	%
Schedule of Deferred Tax Assets	Tax effects of temporary differences that give rise to significant portions of the deferred tax assets are presented below (in thousands):
		December 31,
		2014				2013
	Net operating loss carryforwards	$	31,237			$	45,401
	Income tax credits	4,838				2,379
	Depreciation & amortization	5,615				585
	Accruals & reserves	4,316				1,068
	Stock-based compensation	2,790				1,617
	Total deferred tax assets	48,796				51,050
	Valuation allowance	(48,730		)		(51,003		)
	Net deferred tax assets	$	66			$	47
Summary of Valuation Allowance	The valuation allowance for deferred tax assets consisted of the following activity for the fiscal years ended December 31, 2014, 2013 and 2012 (in thousands):
	Description	Balance at Beginning of Year				Additions				Reductions			Balance at End of Year
	Year ended December 31, 2012	$	32,836			$	12,090			$	—		$	44,926
	Year ended December 31, 2013	44,926				6,077				—			51,003
	Year ended December 31, 2014	$	51,003			$	1,011			$	3,284		$	48,730
Summary of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):
	Balance as of January 1, 2012	$	824
	Gross increase (decrease) on tax positions related to the current year	78
	Balance as of December 31, 2012	902
	Gross increase (decrease) on tax positions related to the prior year	1,434
	Gross increase (decrease) on tax positions related to the current year	589
	Balance as of December 31, 2013	2,925
	Gross increase (decrease) on tax positions related to the prior year	(1,746		)
	Gross increase (decrease) on tax positions related to the current year	274
	Balance as of December 31, 2014	$	1,453

Net_Income_Loss_per_Share_of_C1

Net Income (Loss) per Share of Common Stock (Tables)	12 Months Ended
	Dec. 31, 2014
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:
		Year Ended December 31,
		2014			2013			2012
	Numerator
	Net income (loss) (in thousands)	1,531			(19,305		)	(30,143		)
	Denominator
	Weighted average shares of common stock outstanding used in computing net income (loss) per share, basic	37,563,590			36,209,051			34,776,380
	Dilutive effect of incremental shares and share equivalents	3,433,382			—			—
	Weighted average shares of common stock outstanding used in computing net income (loss) per share, diluted	40,996,972			36,209,051			34,776,380
	Net income (loss) per share:
	Net income (loss) per share, basic	$	0.04		$	(0.53	)	$	(0.87	)
	Net income (loss) per share, diluted	$	0.04		$	(0.53	)	$	(0.87	)
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:
		Year Ended
		December 31,
		2014		2013			2012
	Options to purchase common stock	220,712		3,598,385			4,128,334
	Restricted stock units	12,723		1,906,696			119,507
	Common stock issuable pursuant to the ESPP	—		86,026			21,586
	Total	233,435		5,591,107			4,269,427

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	The supplemental cash flow information consists of the following (in thousands):
		Year Ended
		December 31,
		2014			2013			2012
	Cash paid for interest	$	—		$	—		$	2
	Cash paid for income taxes	$	285		$	188		$	47
	Non-cash investing and financing activities:
	Assets acquired under capital leases	$	(382	)	$	—		$	—
	Changes in accounts payable and accrued liabilities related to property, plant and equipment purchases	$	91		$	(33	)	$	(100	)

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2014
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):
		Year Ended
		December 31,
		2014		2013		2012
	North America	$	134,434	$	89,150	$	56,657
	International	40,044		22,476		19,537
	Total	$	174,478	$	111,626	$	76,194
Revenue By Product	The following table sets forth revenue by product expressed as dollar amounts (in thousands):
		Year Ended
		December 31,
		2014		2013		2012
	System revenue	$	93,015	$	61,359	$	39,145
	Consumable revenue	81,463		50,267		37,049
	Total	$	174,478	$	111,626	$	76,194

Selected_Quarterly_Financial_D1

Selected Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following table presents selected unaudited consolidated financial data for each of the eight quarters in the two-year period ended December 31, 2014. The selected quarterly financial data should be read in conjunction with the Company's consolidated financial statements and the related notes and "Item 7: Management's Discussion and Analysis of Financial Condition and Results of Operations". This information has been derived from the Company's unaudited consolidated financial statements that, in management's opinion, reflect all recurring adjustments necessary to fairly state this information when read in conjunction with the Company's consolidated financial statements and the related notes appearing in the section entitled "Consolidated Financial Statements". Net income (loss) per share-basic and diluted, for the four quarters of each fiscal year may not sum to the total for the fiscal year because of the different number of shares outstanding during each period. The results of operations for any quarter are not necessarily indicative of the results to be expected for any future period.
		Quarter
		First			Second			Third			Fourth
		(In thousands, except share and per share data)
	Year Ended December 31, 2014
	Total revenue	$	30,975		$	47,061		$	45,670		$	50,772
	Gross profit	$	21,959		$	33,401		$	33,115		$	35,939
	Net income (loss)	$	(7,337	)	$	2,769		$	4,782		$	1,317
	Net income (loss) per share, basic	$	(0.20	)	$	0.07		$	0.13		$	0.03
	Shares used in calculation-basic	37,215,697			37,440,537			37,630,222			37,958,395
	Net income (loss) per share, diluted	$	(0.20	)	$	0.07		$	0.12		$	0.03
	Shares used in calculation-diluted	37,215,697			40,597,275			40,926,034			41,434,178
	Year Ended December 31, 2013
	Total revenue	$	19,982		$	26,338		$	29,465		$	35,841
	Gross profit	$	12,634		$	18,460		$	21,229		$	25,114
	Net income (loss)	$	(7,482	)	$	(3,607	)	$	(2,811	)	$	(5,405	)
	Net income (loss) per share, basic and diluted	$	(0.21	)	$	(0.10	)	$	(0.08	)	$	(0.15	)
	Shares used in calculation-basic and diluted	35,890,084			36,045,346			36,206,008			36,686,053

The_Company_and_Basis_of_Prese1

The Company and Basis of Presentation (Details) (Restatement Adjustment [Member], USD $)	3 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Revenue reduction	$0.70
Adjustment Related to Fiscal Year 2013 [Member]
Revenue reduction	$0.40

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Restricted cash	$560,000	$331,000
Impairment of long-lived assets	0	0	0
Advertising expense	7,900,000	8,900,000	12,000,000
Foreign currency transaction gains (losses)	($300,000)	$24,000	($48,000)

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Concentration Of Credit Risk (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at Beginning of Year	$0	$330,000	$40,000
Additions	469,000	59,000	329,000
Reductions	145,000	389,000	39,000
Balance at End of Year	$324,000	$0	$330,000
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Allowance for Doubtful Accounts Receivable [Roll Forward]
Concentration risk, number	1
Concentration risk, percentage	24.00%

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Property Plant And Equipment (Details)	12 Months Ended
	Dec. 31, 2014
Lab Equipment, Tooling, and Molds [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	5 years
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	3 years
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	3 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	5 years
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	5 years
Capitalized Software [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	3 years

Summary_of_Significant_Account6

Summary of Significant Accounting Policies - Warranty (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2014
Direct Customer [Member] | Control Units [Member]
Product Liability Contingency [Line Items]
Product warranty term	1 year	1 year
Direct Customer [Member] | Applicators [Member]
Product Liability Contingency [Line Items]
Product warranty term		1 year
International [Member] | Indirect Customer [Member] | Control Units [Member]
Product Liability Contingency [Line Items]
Product warranty term	3 years	3 years
International [Member] | Indirect Customer [Member] | Applicators [Member]
Product Liability Contingency [Line Items]
Product warranty term	1 year	1 year

Summary_of_Significant_Account7

Summary of Significant Accounting Policies - Comprehensive Income (Loss) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounting Policies [Abstract]
Cumulative translation adjustments	($690)	$77
Unrealized gain (loss) on marketable securities, net of tax	-6	10
Accumulated other comprehensive income (loss)	($696)	$87

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	$21,091
Assets, fair value disclosure	27,153	43,078
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	9,537	14,671
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	17,616	28,407
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	6,062	12,796
Money Market Funds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	6,062	12,796
Money Market Funds [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	0	0
Money Market Funds [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value disclosure	0	0
Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	16,286	18,840
Short-term Investments [Member] | U.S. Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	5,240	6,772
Short-term Investments [Member] | U.S. Agency Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Short-term Investments [Member] | U.S. Agency Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	5,240	6,772
Short-term Investments [Member] | U.S. Agency Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Short-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	1,004	1,001
Short-term Investments [Member] | U.S. Treasury [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Short-term Investments [Member] | U.S. Treasury [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	1,004	1,001
Short-term Investments [Member] | U.S. Treasury [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Short-term Investments [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	7,774	8,870
Short-term Investments [Member] | Corporate Bonds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Short-term Investments [Member] | Corporate Bonds [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	7,774	8,870
Short-term Investments [Member] | Corporate Bonds [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Short-term Investments [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	1,349	999
Short-term Investments [Member] | Commercial Paper [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Short-term Investments [Member] | Commercial Paper [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	1,349	999
Short-term Investments [Member] | Commercial Paper [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Short-term Investments [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	919	1,198
Short-term Investments [Member] | Certificates of Deposit [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	919	1,198
Short-term Investments [Member] | Certificates of Deposit [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Short-term Investments [Member] | Certificates of Deposit [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Long-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	4,805	11,442
Long-term Investments [Member] | U.S. Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	999	6,956
Long-term Investments [Member] | U.S. Agency Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Long-term Investments [Member] | U.S. Agency Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	999	6,956
Long-term Investments [Member] | U.S. Agency Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Long-term Investments [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	500	1,014
Long-term Investments [Member] | U.S. Treasury [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Long-term Investments [Member] | U.S. Treasury [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	500	1,014
Long-term Investments [Member] | U.S. Treasury [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Long-term Investments [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	750	2,795
Long-term Investments [Member] | Corporate Bonds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Long-term Investments [Member] | Corporate Bonds [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	750	2,795
Long-term Investments [Member] | Corporate Bonds [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Long-term Investments [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	2,556	677
Long-term Investments [Member] | Certificates of Deposit [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	2,556	677
Long-term Investments [Member] | Certificates of Deposit [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	0	0
Long-term Investments [Member] | Certificates of Deposit [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, fair value sale securities, fair value disclosure	$0	$0

Balance_Sheet_Components_Inves

Balance Sheet Components - Investments (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$21,097
Fair value	21,091
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	16,289	18,835
Gross unrealized gains	4	6
Gross unrealized losses	-7	-1
Fair value	16,286	18,840
Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	4,808	11,437
Gross unrealized gains	0	8
Gross unrealized losses	-3	-3
Fair value	4,805	11,442
U.S. Agency Securities [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	5,240	6,771
Gross unrealized gains	1	2
Gross unrealized losses	-1	-1
Fair value	5,240	6,772
U.S. Agency Securities [Member] | Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	1,000	6,957
Gross unrealized gains	0	2
Gross unrealized losses	-1	-3
Fair value	999	6,956
U.S. Treasury [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	1,003	1,000
Gross unrealized gains	1	1
Gross unrealized losses	0	0
Fair value	1,004	1,001
U.S. Treasury [Member] | Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	500	1,013
Gross unrealized gains	0	1
Gross unrealized losses	0	0
Fair value	500	1,014
Corporate Bonds [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	7,778	8,867
Gross unrealized gains	2	3
Gross unrealized losses	-6	0
Fair value	7,774	8,870
Corporate Bonds [Member] | Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	752	2,790
Gross unrealized gains	0	5
Gross unrealized losses	-2	0
Fair value	750	2,795
Commercial Paper [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	1,349	999
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	1,349	999
Certificates of Deposit [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	919	1,198
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	919	1,198
Certificates of Deposit [Member] | Long-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	2,556	677
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	$2,556	$677

Balance_Sheet_Components_Inves1

Balance Sheet Components - Investments, Contractual Maturities (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Amortized Cost, Due in one year or less	$16,289
Amortized Cost, Due in one year to five years	4,808
Amortized cost	21,097
Fair Value, Due in one year or less	16,286
Fair Value, Due in one year to five years	4,805
Fair Value	$21,091

Balance_Sheet_Components_Inven

Balance Sheet Components - Inventory (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory, Net [Abstract]
Raw materials	$7,692	$4,520
Finished goods	7,844	3,886
Total inventory	$15,536	$8,406

Balance_Sheet_Components_Prope

Balance Sheet Components - Property and Equipment, Net (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$7,068,000	$5,546,000
Less: Accumulated depreciation and amortization	-4,111,000	-3,594,000
Property and equipment, net	3,724,000	2,158,000
Capital leased assets, gross	382,000
Depreciation	1,100,000	1,000,000	900,000
Lab Equipment, Tooling and Molds [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,766,000	2,071,000
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,337,000	1,562,000
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	984,000	801,000
Capital leased assets, gross	382,000
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,452,000	743,000
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	494,000	334,000
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	35,000	35,000
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$767,000	$206,000

Balance_Sheet_Components_Accru

Balance Sheet Components - Accrued Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued payroll and employee related expenses	$8,386	$7,863
Accrued marketing expenses	2,959	3,739
Accrued royalty	3,612	2,458
Sales and other taxes payable	2,123	1,787
Advance payments from customers	1,908	1,216
Accrued warranty	569	676
Accrued legal expenses	592	284
Other accrued liabilities	1,301	341
Total accrued liabilities	$21,450	$18,364

Balance_Sheet_Components_Warra

Balance Sheet Components - Warranty (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at the beginning of the period	$676	$902
Accruals for warranties issued	284	197
Settlements of warranty claims	-391	-423
Balance at the end of the period	$569	$676

License_Agreement_With_Massach2

License Agreement With Massachusetts General Hospital (Details) (USD $)	12 Months Ended				3 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010	Dec. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Period that agreement remains in full force after last commercial sale with royalty due	1 year
Period to terminate contract with written notice	90 days
Royalty expense, percent of net sales	7.00%
Payments to Acquire Intangible Assets				$1.10
Amortization of intangible assets	0.7	0.7	0.7
License Agreement Milestone 1 [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Payments to Acquire Intangible Assets					1
Cumulative net sales required for milestone payment					70
License Agreement Milestone 2 [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Payments to Acquire Intangible Assets					6
Cumulative net sales required for milestone payment					$200

License_Agreement_With_Massach3

License Agreement With Massachusetts General Hospital - Intangible Asset, Net (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
Purchased technology	$8,050	$8,050
Less: Accumulated amortization	-2,270	-1,569
Intangible asset, net	$5,780	$6,481

License_Agreement_With_Massach4

License Agreement With Massachusetts General Hospital - Estimated Annual Future Amortization Expense (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
2015	$701
2016	701
2017	701
2018	701
2019	701
Thereafter	2,275
Intangible asset, net	$5,780	$6,481

Related_Party_Transactions_Bra

Related Party Transactions - Brazilian Distribution Agreement (Details) (Distributor [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Distributor [Member]
Related Party Transaction [Line Items]
Revenue from related parties	$2.10	$2.30	$2.50
Accounts receivable, related parties	$0.20	$0.20

Commitments_and_Contingencies_1

Commitments and Contingencies - Operating Lease Commitments (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$1,500,000	$1,400,000	$1,200,000
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2015	1,844,000
2016	1,591,000
2017	1,624,000
2018	1,666,000
2019	507,000
Thereafter	84,000
Total future minimum lease payments	$7,316,000

Commitments_and_Contingencies_2

Commitments and Contingencies - Capital Lease Obligations (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Capital Leased Assets [Line Items]
Total capital leased equipment	$382
Less: Accumulated depreciation and amortization	-21
Capital leased equipment, net	361
Amortization of assets acquired under capital leases	21
Future minimum payments under capital leases
2015	132
2016	132
2017	141
Total future payments	405
Less: Amount representing interest	23
Present value of future minimum payments	382
Less: Current portion	120	0
Long term portion	262	0
Computer Equipment [Member]
Capital Leased Assets [Line Items]
Capital leased assets, useful life	3 years
Total capital leased equipment	$382

Commitments_and_Contingencies_3

Commitments and Contingencies - Purchase Commitments (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
Purchase obligation	$4	$6

Commitments_and_Contingencies_4

Commitments and Contingencies - Unrecognized Tax Benefits (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
Unrecognized tax benefits	$21

Commitments_and_Contingencies_5

Commitments and Contingencies - Severance (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2012
Loss Contingencies [Line Items]
Termination benefits				$800,000
Stock-based compensation expense due to modification	0	700,000	700,000
Management [Member]
Loss Contingencies [Line Items]
Termination benefits		300,000	900,000
Stock-based compensation expense due to modification		$700,000	$700,000

Stockholders_Equity_Preferred_

Stockholders' Equity - Preferred Stock (Details) (USD $)	1 Months Ended
	Oct. 31, 2011	Dec. 31, 2014	Dec. 31, 2013
Equity [Abstract]
Preferred stock, shares authorized	50,000,000	50,000,000	50,000,000
Preferred stock, par value (dollars per share)	$0.01	$0.01	$0.01
Conversion of preferred stock into common stock upon initial public offering, shares	24,415,965
Preferred stock, shares issued		0	0
Preferred stock, shares outstanding		0	0

Stockholders_Equity_Common_Sto

Stockholders' Equity - Common Stock (Details) (Common Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2014
	vote
Common Stock [Member]
Class of Stock [Line Items]
Number of votes per share	1
Dividends declared	$0
Dividends paid	$0

StockBased_Compensation_Plans_1

Stock-Based Compensation Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2011	Apr. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares reserved for future purchase under plan	1,851,794	1,200,000
Shares reserved for future issuance	2,685,209	1,086,737	1,103,836
2005 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	0
2011 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance				89,234
Increase in shares at each annual anniversary, percent	5.00%
2012 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance					1,500,000
2011 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock purchase price	85.00%
Common stock available for issuance				470,018
Increase in shares at each annual anniversary, percent	1.00%
Additional shares reserved for future purchase under plan	370,358	150,000
Shares purchased	103,089
Weighted average exercise price of shares purchased (in dollars per share)	14.86
Shares reserved for future issuance	565,387
ISO and NSO [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rate	25.00%
ISO and NSO [Member] | 2005 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
ISO and NSO [Member] | 2005 Equity Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period options may be granted	10 years
ISO and NSO [Member] | 2011 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
ISO and NSO [Member] | 2011 Equity Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period options may be granted	10 years
ISO and NSO [Member] | 2011 Equity Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock purchase price	100.00%
ISO and NSO [Member] | 2012 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
ISO and NSO [Member] | 2012 Stock Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period options may be granted	10 years
ISO and NSO [Member] | 2012 Stock Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock purchase price	100.00%
ISO and NSO [Member] | 10% Stockholder [Member] | 2005 Equity Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock purchase price	110.00%
ISO [Member] | 2005 Equity Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock purchase price	100.00%
ISO [Member] | 10% Stockholder [Member] | 2011 Equity Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock purchase price	110.00%
ISO [Member] | 10% Stockholder [Member] | 2012 Stock Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock purchase price	110.00%
NSO [Member] | 2005 Equity Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock purchase price	85.00%

StockBased_Compensation_Plans_2

Stock-Based Compensation Plans - Stock-based Compensation Activity (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Shares Available for Grant [Roll Forward]
Balance at beginning of period, Shares	1,086,737	1,103,836
Additional shares reserved, Shares	1,851,794	1,200,000
Options granted, Shares	-255,000	-568,987
Options canceled, Shares	41,681	307,738
Balance at end of period, Shares	2,685,209	1,086,737
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance at beginning of period, Shares	3,598,385	4,128,334
Options granted, Shares	255,000	568,987
Options exercised, Shares	-569,283	-791,198
Options canceled, Shares	-41,681	-307,738
Balance at end of period, Shares	3,242,421	3,598,385
Vested and expected to vest, end of period, Shares	3,121,593
Exercisable, end of period, Shares	1,991,577
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Balance at beginning of period, Weighted-Average Exercise Price, Per Share	$5.36	$4.96
Options granted, Weighted-Average Exercise Price, Per Share	$18.42	$6.60
Options exercised, Weighted-Average Exercise Price, Per Share	$4.89	$3.34
Options canceled, Weighted-Average Exercise Price, Per Share	$5.50	$7.36
Balance at ending of period, Weighted-Average Exercise Price, Per Share	$6.47	$5.36
Vested and expected to vest, end of period, Weighted-Average Exercise Price, Per Share	$6.47
Exercisable, end of period, Weighted-Average Exercise Price, Per Share	$5.88
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Balance at end of period, Weighted-Average Remaining Contractual Life	7 years 6 months 26 days
Balance at end of period, Aggregate Intrinsic Value	$69,509
Vested and expected to vest, end of period, Weighted-Average Remaining Contractual Life	7 years 6 months 22 days
Vested and expected to vest, end of period, Aggregate Intrinsic Value	66,927
Exercisable, end of period, Weighted-Average Remaining Contractual Life	7 years 3 months 23 days
Exercisable, end of period, Aggregate Intrinsic Value	$43,865
Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Available for Grant [Roll Forward]
Restricted stock units granted, Shares	-508,729	-1,205,200
Restricted stock units canceled, shares	157,358	163,689
Restricted stock units withheld for tax, shares	311,368	85,661

StockBased_Compensation_Plans_3

Stock-Based Compensation Plans - Stock Options Outstanding (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Stock options outstanding	3,242,421
Options exercisable	1,991,577
$0.55-4.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$0.55
Exercise price, upper limit (in dollars per share)	$4
Stock options outstanding	358,312
Weighted-average remaining contractual life	5 years 6 months
Options exercisable	277,565
4.10-4.62 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$4.10
Exercise price, upper limit (in dollars per share)	$4.62
Stock options outstanding	313,125
Weighted-average remaining contractual life	7 years 10 months 24 days
Options exercisable	123,127
5.04-5.04 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$5.04
Exercise price, upper limit (in dollars per share)	$5.04
Stock options outstanding	1,431,102
Weighted-average remaining contractual life	7 years 7 months 6 days
Options exercisable	923,059
5.06-6.34 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$5.06
Exercise price, upper limit (in dollars per share)	$6.34
Stock options outstanding	407,384
Weighted-average remaining contractual life	8 years
Options exercisable	279,401
6.38-10.20 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$6.38
Exercise price, upper limit (in dollars per share)	$10.20
Stock options outstanding	396,448
Weighted-average remaining contractual life	7 years 3 months 18 days
Options exercisable	256,242
11.30-17.33 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$11.30
Exercise price, upper limit (in dollars per share)	$17.33
Stock options outstanding	81,050
Weighted-average remaining contractual life	8 years
Options exercisable	27,183
17.44-17.44 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$17.44
Exercise price, upper limit (in dollars per share)	$17.44
Stock options outstanding	5,000
Weighted-average remaining contractual life	9 years 2 months 12 days
Options exercisable	0
17.48-17.48 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$17.48
Exercise price, upper limit (in dollars per share)	$17.48
Stock options outstanding	180,000
Weighted-average remaining contractual life	9 years 4 months 24 days
Options exercisable	105,000
20.88-20.88 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$20.88
Exercise price, upper limit (in dollars per share)	$20.88
Stock options outstanding	50,000
Weighted-average remaining contractual life	9 years 1 month 6 days
Options exercisable	0
21.00-21.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit (in dollars per share)	$21
Exercise price, upper limit (in dollars per share)	$21
Stock options outstanding	20,000
Weighted-average remaining contractual life	9 years 2 months 12 days
Options exercisable	0

StockBased_Compensation_Plans_4

Stock-Based Compensation Plans - Restricted Stock Activity (Details) (Restricted stock units [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Restricted stock units [Member]
Number of Units and Awards
Beginning balance (shares)	1,906,696	1,157,450
Restricted stock units granted (shares)	508,729	1,205,200
Restricted stock units released (shares)	-724,986	-292,265
Restricted stock units canceled (shares)	-157,358	-163,689
Ending balance (shares)	1,533,081	1,906,696
Weighted-Average Grant Date Fair Value (in dollars per share)
Beginning Balance (weighted average exercise price) (per share)	$5.60	$5.38
Restricted stock units granted (weighted average exercise price) (per share)	$19.99	$5.57
Restricted stock units released (weighted average exercise price) (per share)	$6.03	$5.35
Restricted stock units canceled (weighted average exercise price) (per share)	$6.50	$4.31
Ending Balance (weighted average exercise price) (per share)	$10.08	$5.60
Awards other than options withheld for tax, shares	311,368	85,661

StockBased_Compensation_Plans_5

Stock-Based Compensation Plans - Stock-Based Compensation Expense (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$9,383,000	$6,660,000	$4,989,000
Stock-based compensation expense due to modification	0	700,000	700,000
Total unrecognized compensation costs	15,100,000			15,100,000
Total unrecognized compensation costs, period of recognition	2 years 2 months
Restatement Adjustment [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Revenue reduction				700,000
Restatement Adjustment [Member] | Adjustment Related to Fiscal Year 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Revenue reduction				400,000
Performance Based Stock Options and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	1,600,000	1,000,000	300,000
Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	833,000	0	0
Cost of revenues [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	443,000	248,000	131,000
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	1,073,000	1,645,000	894,000
Selling and marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	2,917,000	1,783,000	827,000
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$4,117,000	$2,984,000	$3,137,000

StockBased_Compensation_Plans_6

Stock-Based Compensation Plans - Assumptions (Details) (Stock Options [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	4 years 4 months 24 days	4 years 9 months 18 days	5 years 2 months 12 days
Expected volatility	43.00%	51.00%	61.00%
Risk-free interest rate	1.25%	1.02%	0.76%
Expected dividend yield	0.00%	0.00%	0.00%

StockBased_Compensation_Plans_7

Stock-Based Compensation Plans - Employee and Nonemployee Stock-Based Compensation (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, Shares	255,000	568,987
Capitalized stock-based compensation cost	$0	$0	$0
Recognized stock-based compensation tax benefits	87,000	0	0
Stock-based compensation expense related to non-employee grants	600,000	500,000	800,000
Stock-based compensation	9,383,000	6,660,000	4,989,000
Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	833,000	0	0
Restatement Adjustment [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Revenue reduction				700,000
Restatement Adjustment [Member] | Adjustment Related to Fiscal Year 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Revenue reduction				400,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, Shares	250,000	543,987	2,860,927
Weighted-average grant date fair value, stock options (in dollars per share)	$6.77	$6.75	$3.07
Aggregate intrinsic value	3,200,000	6,800,000	6,000,000
Total fair value	4,300,000	4,900,000	2,100,000
Employee Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards other than options granted, Shares	508,729	1,180,200	1,412,066
Weighted-average grant date fair value, awards other than options (in dollars per share)	$19.99	$5.62	$5.70
Fair value of the respective vesting dates	$4,300,000	$1,400,000	$300,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based and Nonemployee Services Transaction, Vesting Period	6 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based and Nonemployee Services Transaction, Vesting Period	2 years

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Matching 401(k) contributions	$1.50	$1.10	$0.70

Income_Taxes_Domestic_And_Fore

Income Taxes - Domestic And Foreign Components of Income (Loss) before Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Domestic income (loss)	$1,443	($19,535)	($30,329)
Foreign income (loss)	319	370	327
Income (loss) before income taxes	$1,762	($19,165)	($30,002)

Income_Taxes_Components_of_Inc

Income Taxes - Components of Income Tax Expense (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current provision:
Federal	$0	$0	$0
State	156	60	37
Foreign	94	61	170
Total current	250	121	207
Deferred provision (benefit):
Federal	0	0	0
State	0	0	0
State	-19	19	-66
Total deferred	-19	19	-66
Total provision	$231	$140	$141

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of The Statutory Federal Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Tax at federal statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	6.00%	2.00%	-1.00%
Non-deductible permanent difference	22.00%	-1.00%	0.00%
Non-deductible executive compensation	150.00%	0.00%	0.00%
Change in valuation allowance	-157.00%	-34.00%	-34.00%
Research & development credits	-47.00%	-2.00%	1.00%
Stock-based compensation	6.00%	-1.00%	-1.00%
Impact of foreign operations	-2.00%	0.00%	0.00%
Effective tax rate	13.00%	-1.00%	0.00%

Income_Taxes_Deferred_Tax_Asse

Income Taxes - Deferred Tax Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$31,237	$45,401
Income tax credits	4,838	2,379
Depreciation & amortization	5,615	585
Accruals & reserves	4,316	1,068
Stock-based compensation	2,790	1,617
Total deferred tax assets	48,796	51,050
Valuation allowance	-48,730	-51,003	-44,926	-32,836
Net deferred tax assets	$66	$47

Income_Taxes_Operating_Loss_Ca

Income Taxes - Operating Loss Carryforwards (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	$109.20
Unrecognized tax benefits resulting from the exercise of employee stock awards	32.6
State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	$97.90

Income_Taxes_Tax_Credit_Carryf

Income Taxes - Tax Credit Carryforward (Details) (Research Tax Credit Carryforward [Member], USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Federal [Member]
Tax Credit Carryforward [Line Items]
Research and development credit carryforwards	$3.40
State [Member]
Tax Credit Carryforward [Line Items]
Research and development credit carryforwards	$3.80

Income_Taxes_Valuation_Allowan

Income Taxes - Valuation Allowance (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Movement in Deferred Tax Asset Valuation Allowance [Roll Forward]
Change in valuation allowance	($2,300,000)	$6,100,000
Balance at Beginning of Year	51,003,000	44,926,000	32,836,000
Additions	1,011,000	6,077,000	12,090,000
Reductions	3,284,000	0	0
Balance at End of Year	$48,730,000	$51,003,000	$44,926,000

Income_Taxes_Unrecognized_Tax_

Income Taxes - Unrecognized Tax Benefits (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Unrecognized tax benefits increase (decrease)	($1,500,000)
Unrecognized tax benefits that would affect effective tax rate due to valuation allowance if recognized	21,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	2,925,000	902,000	824,000
Gross increase on tax positions related to the prior year		1,434,000
Gross decrease on tax positions related to the prior year	-1,746,000
Gross increase on tax positions related to the current year	274,000	589,000	78,000
Ending balance	$1,453,000	$2,925,000	$902,000

Net_Income_Loss_per_Share_of_C2

Net Income (Loss) per Share of Common Stock (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator
Net income (loss) (in thousands)	$1,317	$4,782	$2,769	($7,337)	($5,405)	($2,811)	($3,607)	($7,482)	$1,531	($19,305)	($30,143)
Denominator
Weighted average shares of common stock outstanding used in computing net income (loss) per share, basic	37,958,395	37,630,222	37,440,537	37,215,697					37,563,590	36,209,051	34,776,380
Dilutive effect of incremental shares and share equivalents									3,433,382	0	0
Weighted average shares of common stock outstanding used in computing net income (loss) per share, diluted	41,434,178	40,926,034	40,597,275	37,215,697					40,996,972	36,209,051	34,776,380
Net income (loss) per share:
Net income (loss) per share, basic (in dollars per share)	$0.03	$0.13	$0.07	($0.20)					$0.04	($0.53)	($0.87)
Net income (loss) per share, diluted (in dollars per share)	$0.03	$0.12	$0.07	($0.20)					$0.04	($0.53)	($0.87)

Net_Income_Loss_per_Share_of_C3

Net Income (Loss) per Share of Common Stock - Outstanding Shares of Potentially Dilutive Securities (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (Shares)	233,435	5,591,107	4,269,427
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 (Shares)	220,712	3,598,385	4,128,334
Restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (Shares)	12,723	1,906,696	119,507
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 (Shares)	0	86,026	21,586

Supplemental_Cash_Flow_Informa2

Supplemental Cash Flow Information (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest	$0	$0	$2
Cash paid for income taxes	285	188	47
Non-cash investing and financing activities:
Assets acquired under capital leases	-382	0	0
Changes in accounts payable and accrued liabilities related to property, plant and equipment purchases	$91	($33)	($100)

Segment_Information_Details

Segment Information (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
									business_activity
									manager
									segment
Segment Reporting Information [Line Items]
Number of business activities									1
Number of segment managers held accountable for operations									0
Number of reportable segments									1
Revenue	$50,772	$45,670	$47,061	$30,975	$35,841	$29,465	$26,338	$19,982	$174,478	$111,626	$76,194
Systems [Member]
Segment Reporting Information [Line Items]
Revenue									93,015	61,359	39,145
Consumable Revenues [Member]
Segment Reporting Information [Line Items]
Revenue									81,463	50,267	37,049
North America [Member]
Segment Reporting Information [Line Items]
Revenue									134,434	89,150	56,657
United States [Member]
Segment Reporting Information [Line Items]
Revenue									125,000	83,700	54,700
International [Member]
Segment Reporting Information [Line Items]
Revenue									$40,044	$22,476	$19,537

Selected_Quarterly_Financial_D2

Selected Quarterly Financial Data (unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$50,772	$45,670	$47,061	$30,975	$35,841	$29,465	$26,338	$19,982	$174,478	$111,626	$76,194
Gross profit	35,939	33,115	33,401	21,959	25,114	21,229	18,460	12,634	124,414	77,437	50,688
Net income (loss)	$1,317	$4,782	$2,769	($7,337)	($5,405)	($2,811)	($3,607)	($7,482)	$1,531	($19,305)	($30,143)
Net income (loss) per share, basic (in dollars per share)	$0.03	$0.13	$0.07	($0.20)					$0.04	($0.53)	($0.87)
Shares used in calculation-basic	37,958,395	37,630,222	37,440,537	37,215,697					37,563,590	36,209,051	34,776,380
Net income (loss) per share, diluted (in dollars per share)	$0.03	$0.12	$0.07	($0.20)					$0.04	($0.53)	($0.87)
Shares used in calculation-diluted	41,434,178	40,926,034	40,597,275	37,215,697					40,996,972	36,209,051	34,776,380
Net loss per share attributable to common stockholders, basic and diluted (dollars per share)					($0.15)	($0.08)	($0.10)	($0.21)
Shares used in calculation - basic and diluted					36,686,053	36,206,008	36,045,346	35,890,084