Intersect ENT (XENT) 10-K 25 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Jan. 31, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Trading Symbol	XENT
Entity Registrant Name	Intersect ENT, Inc.
Entity Central Index Key	1,271,214
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		28,176,941
Entity Public Float			$ 707,886,000

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 34,809	$ 13,403
Short-term investments, available-for-sale	89,491	35,040
Accounts receivable, net	11,468	8,337
Inventory	3,949	2,547
Prepaid expenses and other current assets	1,495	951
Total current assets	141,212	60,278
Property and equipment, net	3,183	1,474
Other non-current assets	240	1,201
Total assets	144,635	62,953
Current liabilities:
Accounts payable	1,908	2,128
Accrued compensation	9,588	5,085
Other current liabilities	1,574	898
Total current liabilities	13,070	8,111
Deferred rent	1,334	1,030
Total liabilities	$ 14,404	$ 9,141
Commitments and contingencies (note 8)
Stockholders' equity
Preferred stock, $0.001 par value; Authorized shares: 100,000 at December 31, 2015 and 2014; Issued and outstanding shares: none	$ 0	$ 0
Common stock, $0.001 par value; Authorized shares: 150,000 at December 31, 2015 and 2014; Issued and outstanding shares: 28,159 and 23,379 at December 31, 2015 and 2014, respectively	28	23
Additional paid-in capital	253,450	150,410
Accumulated other comprehensive income	8
Accumulated deficit	(123,255)	(96,621)
Total stockholders' equity	130,231	53,812
Total liabilities and stockholders' equity	$ 144,635	$ 62,953

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	28,159,000	23,379,000
Common stock, shares outstanding	28,159,000	23,379,000

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenue	$ 61,593	$ 38,587	$ 17,931
Cost of sales	12,288	10,223	8,150
Gross profit	49,305	28,364	9,781
Operating expenses:
Selling, general and administrative	59,637	36,111	18,229
Research and development	16,608	10,331	9,518
Total operating expenses	76,245	46,442	27,747
Loss from operations	(26,940)	(18,078)	(17,966)
Interest and other income (expense), net	306	(284)	(403)
Net loss	(26,634)	(18,362)	(18,369)
Other comprehensive income:
Unrealized gain on short-term investments	8
Comprehensive loss	$ (26,626)	$ (18,362)	$ (18,369)
Net loss per share, basic and diluted	$ (1.02)	$ (1.61)	$ (12.57)
Weighted average common shares used to compute net loss per share, basic and diluted	26,159	11,384	1,461

Statements of Convertible Prefe

Statements of Convertible Preferred Stock and Stockholders' (Deficit) Equity - USD ($) shares in Thousands, $ in Thousands	Total	Convertible Preferred Stock [Member]	Series A [Member]Convertible Preferred Stock [Member]	Series D [Member]Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Note Receivable From Related Party [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]
Beginning balance, Value at Dec. 31, 2012	$ (58,720)	$ 60,320			$ 1	$ 1,169			$ (59,890)
Issuance of convertible preferred stock upon exercise of warrants, Value			$ 82
Beginning balance, Shares at Dec. 31, 2012		11,283			1,022
Issuance of convertible preferred stock upon exercise of warrants, Shares			22
Issuance of convertible preferred stock, net of issuance cost and preferred stock financing option, Value				$ 30,358
Issuance of convertible preferred stock, net of issuance cost and preferred stock financing option, Shares				4,396
Issuance of common stock upon exercise of stock options, Value	$ 365				$ 1	364
Issuance of common stock upon exercise of stock options, Shares	740				740
Note receivable from related party	$ (275)						$ (275)
Stock-based compensation expense	382					326	56
Net loss	(18,369)								(18,369)
Ending balance, Value at Dec. 31, 2013	(76,617)	$ 90,760			$ 2	1,859	(219)		(78,259)
Ending balance, Shares at Dec. 31, 2013		15,701			1,762
Issuance of convertible preferred stock upon exercise of warrants, Value			$ 29
Issuance of convertible preferred stock upon exercise of warrants, Shares			3
Conversion of convertible preferred stock to common stock, Value	90,789	$ (90,789)			$ 16	90,773
Conversion of convertible preferred stock to common stock, Shares		(15,704)			15,704
Issuance of common stock upon exercise of stock options, Value	244					244
Conversion of convertible preferred stock warrants to common stock warrants	$ 406					406
Issuance of common stock upon exercise of stock options, Shares	163				163
Issuance of common stock upon initial public/follow-on offering, net of issuance costs, Value	$ 55,802				$ 5	55,797
Issuance of common stock upon initial public/follow-on offering, net of issuance costs, Shares					5,750
Stock-based compensation expense	1,550					1,358	192
Reclass upon forgiveness of note receivable from related party						(27)	$ 27
Net loss	(18,362)								(18,362)
Ending balance, Value at Dec. 31, 2014	$ 53,812				$ 23	150,410			(96,621)
Ending balance, Shares at Dec. 31, 2014	0				23,379
Issuance of common stock upon exercise of stock options, Value	$ 909				$ 1	908
Issuance of common stock upon exercise of stock options, Shares	560				560
Issuance of common stock upon employee stock purchase plan, Values	$ 811					811
Issuance of common stock upon employee stock purchase plan, Shares					53
Issuance of common stock upon exercise of warrants, Value	69					69
Issuance of common stock upon exercise of warrants, Shares					48
Issuance of common stock upon initial public/follow-on offering, net of issuance costs, Value	96,392				$ 4	96,388
Issuance of common stock upon initial public/follow-on offering, net of issuance costs, Shares					4,119
Stock-based compensation expense	4,864					4,864
Unrealized gain on short-term investments	8							$ 8
Net loss	(26,634)								(26,634)
Ending balance, Value at Dec. 31, 2015	$ 130,231				$ 28	$ 253,450		$ 8	$ (123,255)
Ending balance, Shares at Dec. 31, 2015					28,159

Statements of Cash Flows

Statements of Cash Flows - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net loss	$ (26,634)	$ (18,362)	$ (18,369)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation and amortization	826	583	505
Stock-based compensation expense	4,864	1,550	382
Amortization of net investment premium paid	682	112
Loss on sales of short-term investments	20
Change in fair value of convertible preferred stock warrants		198	134
Change in fair value of convertible preferred stock financing option			212
Forgiveness of notes receivable from related party		100	100
Loss on disposal of fixed assets		52	26
Changes in operating assets and liabilities:
Accounts receivable, net	(3,131)	(4,137)	(2,901)
Inventory	(1,402)	(350)	(822)
Prepaid expenses and other current assets	(544)	(541)	3
Other non-current assets		(167)	(2)
Accounts payable	(230)	645	360
Accrued compensation	4,503	2,130	1,051
Other current liabilities and deferred rent	959	233	220
Net cash used in operating activities	(20,087)	(17,954)	(19,101)
Investing activities:
Purchases of short-term investments	(184,672)	(35,152)
Sales of short-term investments	6,516
Maturities of short-term investments	123,011
Purchases of property and equipment	(1,524)	(367)	(467)
Net cash used in investing activities	(56,669)	(35,519)	(467)
Financing activities:
Proceeds from issuance of common stock	1,770	232	122
Proceeds from capital lease financing			106
Repayments related to equipment loans		(1,365)	(636)
Repayments related to capital lease financing		(87)	(18)
Proceeds from public offering, net of issuance costs	96,392	55,802
Proceeds from the exercise of Series A convertible preferred warrants			82
Proceeds from issuance of Series D convertible preferred stock, net of issuance costs			30,146
Net cash provided by financing activities	98,162	54,582	29,802
Net increase in cash and cash equivalents	21,406	1,109	10,234
Cash and cash equivalents:
Beginning of the period	13,403	12,294	2,060
End of the period	34,809	13,403	12,294
Non-cash investing activities:
Lessor funded building improvements	40	961
Property and equipment included in accounts payable	$ 43	33	17
Notes issued to related party for the exercise of stock options			$ 500
Warrants issued for growth capital facility			10
Supplemental cash flow information:
Interest paid		$ 53	$ 93

Organization

Organization	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization Description of Business Intersect ENT, Inc. (the “Company”) is incorporated in the state of Delaware and its facilities are located in Menlo Park, California. The Company is a commercial stage drug-device company committed to improving the quality of life for patients with ear, nose and throat conditions. The Company’s sole commercial products are the PROPEL and PROPEL mini drug releasing implants for patients undergoing sinus surgery to treat chronic sinusitis. The Company received approval from the U.S. Food and Drug Administration (“FDA”) for PROPEL in August 2011 and for PROPEL mini in November 2012. In the first half of 2013, the Company began scaling its U.S. direct commercial presence and currently markets its products only in the United States. Liquidity and Business Risks As of December 31, 2015, the Company had cash, cash equivalents and short-term investments of $124.3 million, and an accumulated deficit of $123.3 million. The Company expects its cash, cash equivalents and short-term investments will be sufficient to fund its operations through at least the next twelve months.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Preparation The financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). 1-for-4 Reverse Stock Split In July 2014, the board of directors and stockholders approved, and the Company filed, an amended and restated certificate of incorporation effecting a 1-for-4 reverse stock split of common stock and all convertible preferred stock. The par value of the common and convertible preferred stock was not adjusted as a result of the reverse stock split. All issued and outstanding common stock, convertible preferred stock, warrants for preferred stock, stock options and per share amounts contained in the financial statements have been retroactively adjusted to reflect this reverse stock split for all periods presented. Initial Public Offering In July 2014, the Company completed its IPO by issuing 5,750,000 shares of common stock, including 750,000 shares pursuant to the full exercise by the underwriters of their option to purchase additional shares, at an offering price of $11.00 per share, for net proceeds of $55.8 million, after deducting underwriting discounts and commissions of $4.5 million and offering expenses of $3.0 million. In connection with the IPO, the Company’s outstanding shares of convertible preferred stock were automatically converted into 15,703,875 shares of common stock and warrants exercisable for convertible preferred stock were automatically converted into warrants exercisable for 53,357 shares of common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability of $0.4 million to additional paid-in capital. Follow-on Public Offering In June 2015, the Company completed its follow-on public offering by issuing 4,119,300 shares of common stock, including 537,300 shares pursuant to the full exercise by the underwriters of their option to purchase additional shares, at an offering price of $25.00 per share, for net proceeds of approximately $96.4 million, after deducting underwriting discounts and commissions of $6.2 million and offering expenses of $0.4 million. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts and disclosures reported in the financial statements. Management uses significant judgment when making estimates related to its common stock valuation and related stock-based compensation, the valuations of the convertible preferred stock warrant liability, convertible preferred stock financing option, as well as certain accrued liabilities. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates. Cash and Cash Equivalents The Company considers all highly liquid securities, readily convertible to cash, that mature within 90 days or less from the date of purchase to be cash equivalents. Short-term Investments, Available-for-Sale Short-term investments, which are available-for-sale, represent highly liquid debt instruments with maturities greater than 90 days at date of purchase. Such investments are recorded at fair value and unrealized holding gains and losses are reported as a separate component of accumulated comprehensive income (loss) in stockholders’ equity until realized. The Company reviews its investment portfolio periodically to assess for other-than-temporary impairment. Should the Company determine that any unrealized losses on the investments are other-than-temporary, the amount of that impairment to be recognized in earnings will depend on whether the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current period credit loss. The specific identification method is used to determine the cost of securities disposed of, with realized gains and losses reflected in interest and other income or expense, as appropriate, in the statement of operations. Fair Value of Financial Instruments The Company measures certain financial assets and liabilities at fair value on a recurring basis, including cash equivalents, short-term investments, the convertible preferred stock warrant liability and the convertible preferred stock financing option. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. A three-tier fair value hierarchy is established as a basis for considering such assumptions and for inputs used in the valuation methodologies in measuring fair value: Level 1 — Observable inputs such as quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 — Include other inputs that are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuation techniques for which all significant inputs are observable in the market or can be derived from observable market data. Where applicable, these models project future cash flows and discount the future amounts to a present value using market-based observable inputs including interest rate curves, foreign exchange rates, and credit ratings. Level 3 — Unobservable inputs that are supported by little or no market activities, which would require the Company to develop its own assumptions. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Cash, Cash Equivalents and Short-term Investments The following is a summary of cash, cash equivalents and short-term investments, available-for-sale, by type of instrument measured at fair value on a recurring basis (in thousands): December 31, 2015 2014 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash $ 2,702 $ — $ — $ 2,702 $ 1,971 $ — $ — $ 1,971 Money market funds 26,856 — — 26,856 11,432 — — 11,432 Corporate debt securities — 57,517 — 57,517 — 28,790 — 28,790 Commercial paper — 37,225 — 37,225 — 6,250 — 6,250 $ 29,558 $ 94,742 $ — $ 124,300 $ 13,403 $ 35,040 $ — $ 48,443 Reported as: Cash and cash equivalents $ 34,809 $ 13,403 Short-term investments, available-for-sale 89,491 35,040 $ 124,300 $ 48,443 There were no transfers in and out of Level 1 and Level 2 fair value measurements during the years ended December 31, 2015 and 2014. Convertible Preferred Stock Warrant Liability The following table sets forth a summary of the changes in the estimated fair value of the Company’s convertible preferred stock warrants, which represent financial instruments with valuations classified as Level 3. When a determination is made to classify a financial instrument within Level 3, the determination is based upon the significance of the unobservable inputs to the overall fair value measurement. However, Level 3 financial instruments typically include, in addition to the unobservable inputs, observable inputs (that is, components that are actively quoted and can be validated to external sources). Accordingly, the expense in the table below includes changes in fair value due in part to observable factors that are part of the Level 3 methodology (in thousands): Fiscal Years Ended 2014 2013 Beginning of the period $ 237 $ 93 Issued — 10 Exercised (29 ) — Reclassified to equity (1) (406 ) — Change in fair value 198 134 End of the period $ — $ 237 (1) In connection with the Company’s IPO in July 2014, warrants for convertible preferred stock were converted to warrants for common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability to additional paid-in capital. The fair value of the convertible preferred stock warrants was determined using the option pricing method, the probability weighted expected return method or Black-Scholes option pricing model using the following assumptions: Fiscal Years Ended 2014 2013 Expected term (years) 2.0 2.0 Expected volatility 46 % 45 % Risk-free interest rate 0.5 % 0.4 % Dividend yield 0.0 % 0.0 % Series D Convertible Preferred Stock Financing Option In February 2013, the Company completed the initial closing of the Series D convertible preferred stock financings. The total net cash proceeds from this initial closing totaled $18.2 million and 2,656,636 shares of Series D convertible preferred stock were issued. In March 2013, the Company completed an additional closing of the Series D convertible preferred stock financings. The total net cash proceeds from this additional closing totaled $2.5 million and 370,129 shares of Series D convertible preferred stock were issued. The March 2013 closing included 72,548 shares purchased by certain employees of the Company for $0.5 million. The Series D convertible preferred stock financing contained a provision that obligated the investors to purchase additional shares (“convertible preferred stock financing option”) at the same price as the initial closing upon notification by the Company that it had achieved an annualized revenue rate of at least $16.0 million over a trailing three-month period. This convertible preferred stock financing option to purchase Series D convertible preferred stock in the future tranche was considered to be a freestanding financial instrument for accounting purposes. Therefore, in February 2013, the Company recorded a financing liability of $0.9 million representing the fair value of this convertible preferred stock financing option at the time of issuance. In October 2013, shortly after achieving the annualized revenue rate, the Company issued the additional 1,369,008 shares of Series D convertible preferred stock to the investors for net proceeds of $9.4 million. Since the convertible preferred stock financing option expired in October 2013 as a result of the issuance of Series D convertible preferred stock, the carrying and fair value of the convertible preferred stock financing option of $1.1 million in October 2013 was reclassified from liability to Series D convertible preferred stock. The Company recorded total charges related to the change in fair value during the year ended December 31, 2013 of $0.2 million related to this financing option liability. The following table sets forth a summary of the changes in the estimated fair value of the Company’s convertible preferred stock financing option, which represents financial instruments with valuations classified as Level 3 (in thousands): Fiscal Year Ended Beginning of the period $ — Issued 885 Exercised (1,097 ) Change in fair value 212 End of the period $ — The fair value of the convertible preferred stock financing liability was determined using the present value methodology with the following assumptions which are categorized as Level 3: February October Total consideration per share $ 1.72 $ 1.72 Additional investment per share 1.72 1.72 Discount rate 20.0 % 20.0 % Probability of achievement 95.0 % 95.0 % Years until milestone achieved 0.5 0.7 Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash equivalents, short-term investments and accounts receivable. The Company believes that the credit risk in its accounts receivable is mitigated by its credit evaluation process, relatively short collection terms and dispersion of its customer base. The Company generally does not require collateral and losses on accounts receivable have historically been within management’s expectations. The Company’s investment policy limits investments to certain types of debt securities issued by the U.S. government, its agencies, and institutions with investment-grade credit ratings, as well as corporate debt or commercial paper issued by the highest quality financial and non-financial companies, and places restrictions on maturities and concentration by type and issuer. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash and cash equivalents and issuers of investments to the extent recorded on the balance sheets. However, as of December 31, 2015 and 2014, the Company has limited its credit risk associated with cash, cash equivalents and short-term investments by placing its investments with banks it believes are highly creditworthy and with highly rated investments. Allowance for Doubtful Accounts The Company will provide for uncollectible accounts receivable by recording an allowance for doubtful accounts for accounts receivable deemed uncollectible. The Company evaluates the collectability of its accounts receivable based on known collection risks and historical experience. In circumstances where the Company is aware of a specific customer’s inability to meet its financial obligations to the Company (e.g., bankruptcy filings, substantial downgrading of credit ratings), the Company records a specific allowance for bad debts against amounts due to reduce the carrying amount of accounts receivable to the amount it reasonably believes will be collected. If circumstances change, such as higher-than-expected defaults or an unexpected material adverse change in a major customer’s ability to meet its financial obligations, the Company’s estimates of the recoverability of the amounts due could be reduced by a significant amount. Based on the high creditworthiness of the customers that the Company sells to, the Company has experienced no significant collection issues. Inventory Inventory is valued at the lower of cost or market, computed on a first-in, first-out basis, or net realizable value. This requires the Company to make estimates regarding the recoverability of its inventory, including an assessment of excess or obsolete inventory. The Company determines excess and obsolete inventory based on future demand for products within a specified time horizon, generally 12 months, product life cycles and expiration of inventory prior to sale. Any inventory written down creates a new cost basis for the inventory value. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is determined using the straight-line method over the estimated useful lives of the respective assets, generally three to five years. Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated useful lives or the term of the lease. Amortization of assets under capital leases is included in depreciation and amortization expense. Maintenance and repairs are charged to operations as incurred. Impairment of Long-lived Assets Long-lived assets consists primarily of property and equipment and are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require that a long-lived asset be tested for possible impairment, the Company compares the undiscounted cash flows expected to be generated by the asset group to the carrying amount of the asset group. If the carrying amount of the long-lived asset is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying amount exceeds its fair value. The Company determines fair value using the income approach based on the present value of expected future cash flows or other appropriate measures of estimated fair value. The Company’s cash flow assumptions consider historical and forecasted revenue and operating costs and other relevant factors. Since inception, the Company has not recorded impairment charges on long-lived assets. Convertible Preferred Stock Warrant Liability For a warrant classified as a derivative liability, the fair value of that warrant was recorded on the balance sheet at the inception of such classification and adjusted to fair value at each financial reporting date. The changes in the fair value of the warrants were recorded in the statement of operations and comprehensive loss as a component of interest and other income or expense, as appropriate. The Company continued to adjust the carrying value of the convertible preferred stock warrant liability for changes in the fair value of the warrants until the earlier of: the exercise of the warrants, at which time the liability was reclassified to temporary equity; the conversion of the underlying convertible preferred stock into common stock, at which time the liability was reclassified to stockholders’ equity (deficit); or the expiration of the warrant, at which time the entire amount would have been reversed and reflected in the statement of operations and comprehensive loss. In connection with the Company’s IPO in July 2014, the warrants for convertible preferred stock were converted to warrants for common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability of $0.4 million to additional paid-in capital. Convertible Preferred Stock Financing Option For a freestanding option to purchase in a future round of financing, the fair value of that option was recorded on the balance sheet at the inception of such classification and adjusted to fair value at each financial reporting date. The change in the fair value of the convertible preferred stock financing option was recorded in the statement of operations and comprehensive loss as a component of interest and other income or expense, as appropriate. The Company adjusted the carrying value of the convertible preferred stock financing option liability for changes in the fair value of the option and continued to do so until the earlier of when the convertible preferred stock financing option was exercised or expired. Revenue Recognition Revenue is derived from the sale of PROPEL and PROPEL mini to hospitals and ambulatory surgery centers in the United States. The Company recognizes revenue when persuasive evidence of an arrangement exists, product delivery has occurred or there is no further obligation, pricing is fixed or determinable and collection is reasonably assured. The Company must make significant assumptions regarding the future collectability of amounts receivable from customers to determine whether revenue recognition criteria have been met. If collectability is not reasonably assured at the time of shipment, the Company defers revenue until such criteria have been met. In general, the Company’s standard terms and conditions of sale do not allow for product returns. The Company expenses shipping and handling costs as incurred and includes them in the cost of sales. In those cases where shipping and handling costs are billed to customers, the Company classifies the amounts billed as a component of revenue. Cost of Sales Cost of sales consists primarily of manufacturing overhead costs, material costs and direct labor. A significant portion of the Company’s cost of sales currently consists of manufacturing overhead costs. These overhead costs include the cost of quality assurance, material procurement, inventory control, facilities, equipment and operations supervision and management. Cost of sales also includes depreciation expense for production equipment and certain direct costs such as shipping costs. Research and Development Research and development expenses consist primarily of product development, clinical and regulatory affairs, consulting services and other costs associated with products and technologies in development. These expenses include employee compensation, stock-based compensation, supplies, quality assurance and related travel and facility costs. Clinical expenses include clinical trial design, clinical site reimbursement, data management and travel expenses, and the cost of manufacturing products for clinical trials. Common Stock Valuation and Stock-based Compensation The Company maintains a payment equity incentive plans to provide long-term incentives for employees, consultants and members of the board of directors. The plan allows for the issuance of non-statutory and incentive stock options to employees and non-statutory stock options to consultants and non-employee directors. The Company is required to determine the fair value of equity incentive awards and recognize compensation expense for all equity incentive awards made to employees and directors, including employee stock options. Stock-based compensation expense is recognized over the requisite service period in the statements of operations and comprehensive loss and is based on awards ultimately expected to vest, therefore the amount of expense has been reduced for estimated forfeitures. The Company uses the straight-line method for expense attribution, except for awards issued with performance-based conditions which require an accelerated attribution method over the requisite performance and service periods. Under the applicable accounting guidance for equity incentive awards issued to non-employees, the date at which the fair value of such awards is measured is equal to the earlier of: 1) the date at which a commitment for performance by the counterparty to earn the equity instrument is reached; or 2) the date at which the counterparty’s performance is complete. The Company recognizes stock-based compensation expense for the fair value of the vested portion of the non-employee awards in the statements of operations and comprehensive loss. The fair value of options granted to non-employees is remeasured as the options vest. The valuation model used for calculating the fair value of awards for stock-based compensation expense is the Black-Scholes option-pricing model (the “Black-Scholes model”). The Black-Scholes model 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), the volatility of common stock and an assumed risk-free interest rate. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected term of the option. Since stock-based compensation expense is based on awards ultimately expected to vest, potential forfeitures are estimated based on the Company’s historical forfeiture experience and an analysis of similar companies. To the extent actual forfeitures differ from the estimates, the Company records the difference as a cumulative adjustment in the period that the estimates are revised. Deferred Rent Rent expense is recognized on a straight-line basis over the non-cancelable term of the Company’s operating lease and, accordingly, the Company records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. The Company also records lessor-funded lease incentives, such as leasehold improvements, as a deferred rent liability, which is amortized as a reduction of rent expense over the non-cancelable term of its operating lease. Advertising Expenses The Company expenses the costs of advertising, including promotional expenses, as incurred. Advertising expenses were $0.3 million, $0.1 million and $46,000 during the years ended December 31, 2015, 2014 and 2013, respectively. Income Taxes The Company accounts for income taxes under the liability method. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates that will be in effect when the differences are expected to reverse. Valuation allowances against deferred tax assets are established when necessary to reduce deferred tax assets to the amounts expected to be realized. Currently, the Company has recorded a full valuation allowance against its deferred tax assets and there is no provision for income taxes, as the Company has incurred operating losses to date. The Company’s policy is to record interest and penalties expense related to uncertain tax positions as “other expense” in the statement of operations. Net Loss per Share Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and dilutive potential shares of common stock outstanding during the period. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods as all potentially dilutive shares consisting of convertible preferred stock, stock options and warrants were antidilutive in those periods. The Company allocates no loss to participating securities because the participating securities have no contractual obligation to share in the losses of the Company. The shares of the Company’s convertible preferred stock participate in any dividends declared by the Company and are therefore considered to be participating securities. Net loss per share was determined as follows (in thousands, except per share amounts): Fiscal Years Ended December 31, 2015 2014 2013 Net loss $ (26,634 ) $ (18,362 ) $ (18,369 ) Weighted average common stock outstanding (1) 26,159 11,384 1,461 Net loss per share, basic and diluted (1) $ (1.02 ) $ (1.61 ) $ (12.57 ) (1) In connection with the Company’s IPO in July 2014, the convertible preferred stock outstanding was converted into 15,703,875 shares of common stock on a one-for-one basis. The following potentially dilutive securities outstanding have been excluded from the computations of weighted average shares outstanding because such securities have an antidilutive impact due to losses reported, in common stock equivalent shares (in thousands): Fiscal Years Ended December 31, 2015 2014 2013 Convertible preferred stock outstanding (1) — — 15,701 Convertible preferred stock warrants (1) — — 57 Common stock warrants — 66 — Common stock options 2,946 2,458 1,928 ESPP 252 — — 3,198 2,524 17,686 (1) In connection with the Company’s IPO in July 2014, the convertible preferred stock outstanding was converted into 15,703,875 shares of common stock and the convertible preferred stock warrants were converted into common stock warrants, both on a one-for-one basis. Comprehensive Loss Comprehensive loss consists of net loss and changes in unrealized gains and losses on short-term investments, available-for-sale. Segment, Geographical and Customer Concentration The Company has one operating segment. All of the Company’s assets and revenue are based in the U.S. No single customer accounted for more than 10% of its revenue during the years ended December 31, 2015, 2014 and 2013, and no single customer accounted for more than 10% of its accounts receivable at December 31, 2015 and 2014. Recent Accounting Pronouncements In August 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date Revenue from Contracts with Customers In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern In June 2014, the FASB issued ASU No. 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period

Composition of Certain Financia

Composition of Certain Financial Statement Items	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Composition of Certain Financial Statement Items	3. Composition of Certain Financial Statement Items Accounts Receivable (in thousands): December 31, 2015 2014 Accounts receivable $ 11,554 $ 8,337 Allowance for doubtful accounts (86 ) — $ 11,468 $ 8,337 Inventory (in thousands): December 31, 2015 2014 Raw materials $ 911 $ 761 Work-in-process 187 141 Finished goods 2,851 1,645 $ 3,949 $ 2,547 Property and Equipment (in thousands): December 31, 2015 2014 Computer equipment and software $ 632 $ 546 Furniture and office equipment 417 158 Laboratory equipment 3,191 2,276 Leasehold improvements 1,256 128 5,496 3,108 Less: accumulated depreciation and amortization (2,313 ) (1,634 ) $ 3,183 $ 1,474

Cash, Cash Equivalents and Shor

Cash, Cash Equivalents and Short-term Investments	12 Months Ended
	Dec. 31, 2015
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Short-term Investments	4. Cash, Cash Equivalents and Short-term Investments The following is a summary of cash, cash equivalents and short-term investments, available-for-sale, by type of instrument (in thousands): December 31, 2015 2014 Amortized Cost Gross Unrealized Estimated Fair Value Amortized Cost Gross Unrealized Estimated Fair Value Gains Losses Gains Losses Cash $ 2,702 $ — $ — $ 2,702 $ 1,971 $ — $ — $ 1,971 Money market funds 26,856 — — 26,856 11,432 — — 11,432 Corporate debt securities 57,546 — (29 ) 57,517 28,797 3 (10 ) 28,790 Commercial paper 37,188 37 — 37,225 6,243 7 — 6,250 $ 124,292 $ 37 $ (29 ) $ 124,300 $ 48,443 $ 10 $ (10 ) $ 48,443 Reported as: Cash and cash equivalents $ 34,809 $ 13,403 Short-term investments, available-for-sale 89,491 35,040 $ 124,300 $ 48,443 Management has the intent and ability, if necessary, to liquidate any of the Company’s investments in order to meet the Company’s liquidity needs in the next 12 months. Accordingly, investments with contractual maturities greater than one year from the date of purchase, if any, are available-for-sale and classified as short-term on the accompanying balance sheets. As of December 31, 2015 and 2014, the Company had no investments with a maturity of greater than one year. Based on an evaluation of securities that have been in a loss position, the Company did not recognize any other-than-temporary impairment charges during the years ended December 31, 2015, 2014 and 2013. The Company considered various factors which included a credit and liquidity assessment of the underlying securities and the Company’s intent and ability to hold the underlying securities until the estimated date of recovery of its amortized cost

Equipment Loans

Equipment Loans	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Equipment Loans	5. Equipment Loans In September 2012, the Company entered into an equipment loan with an aggregate principal amount of $2.0 million, all of which was drawn down in December 2012. Payments were being made in monthly installments over a 36-month period with an annual interest rate of 5.1%. In August 2014, the amount outstanding under this equipment loan of $0.9 million was fully repaid. In April 2013, the Company entered into a capital lease for a principal amount of $0.1 million. Payments were made in monthly installments over a 38-month period with an interest rate of 14.88%. In November 2014, the amount outstanding under this equipment loan of $59,000 was fully repaid.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Stockholders' Equity	6. Stockholders’ Equity 2014 Equity Incentive Plan In July 2014, the Company’s board of directors approved the 2014 Equity Incentive Plan (“2014 Plan”). The 2014 Plan became effective on the effective date of the IPO, at which time the Company ceased making awards under the 2013 Equity Incentive Plan (the “2013 Plan”). Under the 2014 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and certain other awards to individuals who are employees, officers, directors or consultants of the Company. A total of 4,750,000 shares of common stock were initially reserved for issuance under the 2014 Plan. The number of shares of common stock reserved for issuance under the 2014 Plan will automatically increase on January 1 of each year, beginning on January 1, 2015, and continuing through and including January 1, 2024, by 3% of the total number of shares of the Company’s capital stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares determined by the Company’s board of directors. The maximum number of shares that may be issued upon the exercise of ISOs under the 2014 Plan is 10.0 million. Incentive stock options (“ISOs”) and non-statutory stock options (“NSOs”) may be granted with exercise prices at no less than 100% of the fair value of the common stock on the date of grant. Options granted to a 10% stockholder shall be at no less than 110% of the fair value and ISO stock option grants to such 10% stockholders expire five years from the date of grant. ISOs granted under the 2014 Plan generally vest 25% after the completion of 12 months of service and the balance vests in equal monthly installments over the next 36 months of service and expire 10 years from the grant date, unless subject to provisions regarding 10% stockholders. NSOs vest per the specific agreement and expire 10 years from the date of grant. New shares are issued upon exercise of options under the stock plan. On January 1, 2015, the total number of shares of common stock reserved for issuance increased by 701,328 shares to 5,451,328 shares. 2013 Equity Incentive Plan The Company ceased making awards under the 2013 Plan upon the effective date of the Company’s IPO. Under the 2013 Plan approved by the Company’s Board of Directors in September 2013, shares of common stock were reserved for the issuance of ISOs, NSOs, stock bonuses and rights to acquire restricted stock to employees, officers, directors and consultants of the Company. There were 10,000 options issued with 100% of the shares vested as of the date of grant during the year ended December 31, 2014 and no options issued with 100% of the shares vested as of the date of grant during the year ended December 31, 2013. Options outstanding under the 2013 Plan will expire upon forfeiture. As of December 31, 2015, 0.5 million options were outstanding under the 2013 Plan. The 2013 Plan was the successor to the 2003 Equity Incentive Plan (“2003 Plan”) which expired in September 2013. Options outstanding under the 2003 Plan will expire upon forfeiture. A summary of the Company’s stock option activity and related information is as follows (in thousands, except price data): Fiscal Years Ended December 31, 2015 2014 2013 Options Price Options Price Options Price Outstanding, beginning of period 2,458 $ 4.84 1,928 $ 1.08 1,594 $ 0.88 Granted 1,181 22.90 819 12.88 1,033 1.20 Granted - below fair market value — — — — 94 1.32 Exercised (560 ) 1.59 (163 ) 1.42 (740 ) 0.84 Forfeited (85 ) 20.27 (126 ) 3.86 (53 ) 1.08 Expired (48 ) 5.58 — — — — Outstanding, end of period 2,946 12.24 2,458 4.84 1,928 1.08 Vested and expected to vest 2,853 11.84 2,338 4.67 1,752 1.08 Exercisable 1,547 6.35 1,612 2.66 1,314 1.00 As of December 31, 2015, the aggregate pre-tax intrinsic value of options outstanding was $31.5 million and options outstanding and exercisable was $25.2 million, the weighted average remaining contractual term of options outstanding were 8.1 years and options outstanding and exercisable were 7.4 years. The aggregate pre-tax intrinsic value of options exercised was $12.7 million, $1.5 million and $0.3 million during the years ended December 31, 2015, 2014 and 2013, respectively. 2014 Employee Stock Purchase Plan In July 2014, the Company’s board of directors approved the 2014 Employee Stock Purchase Plan (“2014 ESPP”). The 2014 ESPP became effective on the effective date of the IPO. A total of 496,092 shares were initially reserved for issuance under the 2014 ESPP. In March 2015, the Company approved the implementation of the 2014 ESPP to begin in May 2015. During the year ended December 31, 2015, 53,242 shares were issued. Common Stock Warrant In May 2015, warrants issued in connection with the purchase of three sinus irrigation tool patents from Medilyfe Inc. in March 2009 were fully exercised for 43,750 shares of the Company’s common stock at $1.00 per share. A member of the Company’s Medical Advisory Board holds an executive-level position in Medilyfe Inc., a Canadian corporation. Convertible Preferred Stock In connection with the Company’s IPO in July 2014, the convertible preferred stock, issued in series, was converted into 15,703,875 share of common stock on a one-for-one basis, resulting in the reclassification of the related redeemable convertible preferred stock of $90.8 million to common stock and additional paid-in capital. Convertible Preferred Stock Warrants In connection with the Company’s IPO in July 2014, the warrants for convertible preferred stock were converted to warrants for common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability of $0.4 million to additional paid-in capital. In January 2015, warrants issued in connection with a venture loan to purchase 47,554 shares of Series A convertible preferred stock were exercised for common stock through a cashless exercise provision. Net shares of 39,961 were issued and 7,593 shares were withheld for the exercise price. In February 2015, warrants issued in connection with the loan and security agreement (“Loan Agreement”) with Silicon Valley Bank in August 2013 to purchase 5,803 shares of Series D convertible preferred stock were exercised for common stock through a cashless exercise provision. Net shares of 4,024 were issued and 1,779 shares were withheld for the exercise price. The Company cancelled the Loan Agreement in August 2014 and had not received any advances under the Loan Agreement. In March 2014, warrants to purchase 4,076 shares of Series A convertible preferred stock were exercised through a cashless exercise provision. Net shares of 2,431 were issued and 1,645 shares were withheld for the exercise price. The outstanding convertible preferred stock was subsequently converted to common stock in connection with the Company’s IPO in July 2014. In January 2013, warrants to purchase 22,418 shares of Series A convertible preferred stock were exercised at a price of $3.68 per share.

Stock-Based Compensation Expens

Stock-Based Compensation Expense	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Expense	7. Stock-Based Compensation Expense Total stock-based compensation expense recognized is as follows (in thousands): Fiscal Years Ended December 31, 2015 2014 2013 Cost of sales $ 280 $ 49 $ 21 Selling, general and administrative 3,837 1,361 273 Research and development 747 140 88 $ 4,864 $ 1,550 $ 382 As of December 31, 2015, the amount of unearned stock-based compensation currently estimated to be expensed from now through the year 2019 related to unvested employee stock-based payment awards was $13.2 million and the weighted average period over which the unearned stock-based compensation is expected to be recognized was 2.8 years. If there are any modifications or cancellations of the underlying unvested securities, the Company may be required to accelerate, increase or cancel any remaining unearned stock-based compensation expense. Future stock-based compensation expense and unearned stock-based compensation will increase to the extent that the Company grants additional share-based payments. The Company estimates the fair value of stock-based compensation on the date of grant using the Black-Scholes option-pricing model. The Black-Scholes model determines the fair value of stock-based payment awards based on the fair market value of the Company’s common stock on the date of grant and is affected by assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, the fair market value of the Company’s common stock, volatility over the expected term of the awards and actual and projected employee stock option exercise behaviors. The Company has opted to use the “simplified method” for estimating the expected term of options, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option. Due to the Company’s limited operating history and a lack of company specific historical and implied volatility data, the Company has based its estimate of expected volatility on the historical volatility of a group of similar companies that are publicly traded. When selecting these public companies on which it has based its expected stock price volatility, the Company generally selected companies with comparable characteristics to it, including enterprise value, stages of clinical development, risk profiles, position within the industry and with historical share price information sufficient to meet the expected life of the stock-based awards. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the share-based payments. The Company will continue to analyze the historical stock price volatility and expected term assumptions as more historical data for the Company’s common stock becomes available. The risk-free rate assumption is based on the U.S. Treasury instruments with maturities similar to the expected term of the Company’s stock options. The expected dividend assumption is based on the Company’s history of not paying dividends and its expectation that it will not declare dividends for the foreseeable future. As stock-based compensation expense is based on awards ultimately expected to vest, the amount of expense has been reduced for estimated forfeitures. Potential forfeitures are estimated based on the Company’s historical forfeiture experience and an analysis of similar companies. To the extent actual forfeitures differ from the estimates, the Company records the difference as a cumulative adjustment in the period that the estimates are revised. The fair value of options granted to employees or directors during the periods presented below were estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Fiscal Years Ended 2015 2014 2013 Expected term (years) 6.0 6.0 6.0 Expected volatility 48 % 56 % 67 % Risk-free interest rate 1.6 % 1.9 % 1.6 % Dividend yield 0.0 % 0.0 % 0.0 % Weighted average fair value $ 10.66 $ 6.80 $ 0.96 The fair value of options granted under the 2014 ESPP to employees was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Fiscal Year Ended Expected term (years) 1.3 Expected volatility 38 % Risk-free interest rate 0.4 % Dividend yield 0.0 % Weighted average fair value $ 7.29 Option Modification In April 2013, options held by the President and Chief Executive Officer, Ms. Earnhardt, a related party, were modified to permit exercise with promissory notes of up to $0.5 million. Under the terms of the notes, one quarter of the principal and interest was to be forgiven on each anniversary date of the note as long as Ms. Earnhardt remains the Company’s Chief Executive Officer. In addition, the entire principal and interest of the notes was to be forgiven on the earlier of an initial public offering or the closing of a liquidation event (as defined in the certificate of incorporation), in each case where total proceeds payable to the Company or its stockholders is greater than $200.0 million. The Company had the option to accelerate the maturity date if, at the Company’s reasonable discretion, such acceleration may be necessary due to any applicable law, rule or regulation, including, without limitation, the Sarbanes-Oxley Act of 2002. The economic effect of the modification was equivalent to converting options to purchase 0.6 million shares to a grant of restricted stock with four-year vesting and a contingent vesting acceleration provision. The incremental cost of the modification was $0.3 million, of which $50,000, $0.2 million and $50,000 was recognized during the years ended December 31, 2015, 2014 and 2013, respectively. In June 2014, the entire principal amount and all accrued and unpaid interest of the loan was forgiven in full. In connection with the forgiveness of the note, the unamortized modification cost relating to the vested options of $0.2 million was immediately recognized. The remaining unamortized modification cost of $0.1 million was amortized over the remaining vesting period.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Contingencies In the normal course of business, the Company enters into contracts and agreements 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. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. Indemnification The Company’s amended and restated certificate of incorporation contains provisions limiting the liability of directors, and its amended and restated bylaws provide that the Company will indemnify each of its directors to the fullest extent permitted under Delaware law. The Company’s amended and restated certificate of incorporation and amended and restated bylaws also provide its board of directors with discretion to indemnify its officers and employees when determined appropriate by the board. In addition, the Company has entered and expects to continue to enter into agreements to indemnify its directors and executive officers. Litigation The Company is not currently a party to any material legal proceedings. The Company may at times be involved in litigation and other legal claims in the ordinary course of business. When appropriate in the Company’s estimation, it may record reserves in its financial statements for pending litigation and other claims. Building Lease As of December 31, 2015, the Company has one leased facility under an operating lease agreement entered into in March 2012. In December 2014, the operating lease agreement was amended for an additional 17,900 square feet for a total of 50,400 square feet and the expiration was extended to May 31, 2020. Rental payments are charged to expense on a straight-line basis over the period of the lease. The lease agreement requires the Company to pay executory costs such as real estate taxes, insurance and repairs, and includes a renewal provision allowing the Company to extend this lease for an additional three years at 95% of the then-current fair market rental rate. Because of the terms of the amended lease agreement, the Company is the deemed owner, for accounting purposes only, of the building improvements. Accordingly, the Company recorded an asset of $1.0 million, representing the total costs of the building improvements payable by the lessor, the legal owner of the building, with a corresponding offset recorded as deferred rent. The building improvements are being amortized over the life of the lease. Future minimum annual operating lease payments are as follows (in thousands): Fiscal Years Ending December 31, December 31, 2016 $ 1,494 2017 1,536 2018 1,580 2019 1,625 2020 685 $ 6,920 Rent expense was $1.9 million, $1.3 million and $1.4 million during the years ended December 31, 2015, 2014 and 2013, respectively. Purchase Commitments As of December 31, 2015, the Company had commitments to suppliers for purchases totaling $1.9 million.

Employee Retirement Plan

Employee Retirement Plan	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Retirement Plan	9. Employee Retirement Plan In January 2007, the Company established a qualified retirement plan under section 401(k) of the Internal Revenue Code (“IRC”) under which participants may contribute up to 100% of their eligible compensation, subject to maximum deferral limits specified by the IRC. The Company may make a discretionary profit sharing contribution to each eligible employee, subject to limits specified by the IRC, on an annual basis, provided the employee is employed with the Company on the last day of the plan year which is December 31. In addition, the Company may also make matching contributions of up to 3% of an employee’s eligible compensation. The Company’s contributions will vest 25% per year over four years. In January 2015, the Company approved the implementation of matching contributions to begin in April 2015. Total matching contributions were $0.2 million during the year ended December 31, 2015.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The Company has a history of losses and therefore has made no provision for income taxes. The amount computed by applying the federal statutory rate to loss before taxes reconciles to the provision for income taxes is as follows (in thousands): Fiscal Years Ended December 31, 2015 2014 2013 Tax at federal statutory rate $ (9,056 ) $ (6,243 ) $ (6,245 ) State tax, net of federal benefit (589 ) (1,264 ) (826 ) Permanent items 675 515 368 R&D tax credit (559 ) (315 ) (584 ) Other — 12 (2 ) Change in valuation allowance 9,529 7,295 7,289 $ — $ — $ — Significant components of net deferred tax assets are as follows (in thousands): December 31, 2015 2014 Deferred tax assets: Net operating losses $ 40,136 $ 33,912 R&D tax credit 3,691 2,888 Accruals and other 5,296 2,465 49,123 39,265 Deferred tax liabilities: Depreciation and amortization (391 ) (62 ) (391 ) (62 ) Net deferred tax asset: 48,732 39,203 Valuation allowance (48,732 ) (39,203 ) $ — $ — Deferred income taxes reflect the tax effects of net operating loss (“NOL”) and tax credit carryforwards and the net temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Realization of the deferred tax assets is dependent upon the generation of future taxable income, if any, the amount and timing of which are uncertain. Based on available objective evidence, management believes it is more likely than not that the deferred tax assets are not recognizable and will not be recognizable until the Company has sufficient taxable income. Accordingly, the net deferred tax assets have been fully offset by a valuation allowance. The valuation allowance increased by $9.5 million and $7.3 million during the years ended December 31, 2015 and 2014, respectively. NOL carryforwards created by excess tax benefits from the exercise of stock options are not recorded as deferred income tax assets. To the extent such NOL carryforwards are utilized, the benefits realized will increase stockholders’ equity. As of December 31, 2015, the Company’s federal NOL carryforwards of $112.4 million will expire at various dates beginning in 2023, if not utilized, and federal research and development tax credits of $3.0 million will begin to expire in 2023. In addition, NOL carryforwards for state income tax purposes of $55.9 million began to expire in 2015 and state research and development tax credits of $2.5 million do not expire. Utilization of the NOL carryforwards may be subject to an annual limitation due to the ownership change limitations provided by the Internal Revenue Code of 1986 and similar state provisions. The annual limitation may result in the expiration of the NOL before utilization. The Company had unrecognized tax benefit of $1.1 million and $0.9 million as of and December 31, 2015 and 2014, respectively, all of which is offset by a full valuation allowance. These unrecognized tax benefits, if recognized, would not affect the effective tax rate. There was no interest or penalties accrued at the adoption date and at December 31, 2015. A reconciliation of the change in the unrecognized tax benefit during the year is as follows (in thousands): December 31, 2015 2014 2013 Beginning of year $ 861 $ 715 $ 505 Additions for tax positions related to: Current year 227 140 210 Prior years 6 6 — End of year $ 1,094 $ 861 $ 715 The Company does not expect a significant change to its unrecognized tax benefits over the next twelve months. The unrecognized tax benefits may increase or change during the next twelve months for items that arise in the ordinary course of business. The Company files income tax returns in the U.S. federal and various state jurisdictions. Tax years beginning in 2004 through 2015 remain open to examination by the major taxing authorities to which the Company is subject to. The Company’s policy is to record interest related to uncertain tax positions as interest expense and any penalties as other expense in its statements of operations and comprehensive loss. The Company has not recorded any interest expense or penalties associated with unrecognized tax benefits.

Supplemental Quarterly Financia

Supplemental Quarterly Financial Information	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Supplemental Quarterly Financial Information	Supplemental Quarterly Financial Information (unaudited) The following table sets forth unaudited statements of operations data for each of the Company’s last eight quarters. This quarterly information is unaudited and has been prepared on the same basis as the annual financial statements. In the Company’s opinion, this quarterly information reflects all adjustments necessary for a fair presentation of the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period. Fiscal Years Ended December 31, 2015 2014 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Revenue $ 13,372 $ 15,198 $ 14,232 $ 18,791 $ 7,497 $ 8,565 $ 9,100 $ 13,425 Cost of sales 2,792 2,904 2,877 3,715 2,360 2,320 2,576 2,967 Gross profit 10,580 12,294 11,355 15,076 5,137 6,245 6,524 10,458 Gross margin 79 % 81 % 80 % 80 % 69 % 73 % 72 % 78 % Operating expenses: Sales, general and administrative 12,620 14,117 16,420 16,480 6,658 8,291 9,667 11,495 Research and development 3,326 4,038 4,799 4,445 2,577 2,377 2,758 2,619 Total operating expenses 15,946 18,155 21,219 20,925 9,235 10,668 12,425 14,114 Loss from operations (5,366 ) (5,861 ) (9,864 ) (5,849 ) (4,098 ) (4,423 ) (5,901 ) (3,656 ) Interest and other income (expense), net (1) 28 48 126 104 (311 ) 41 16 (30 ) Net loss $ (5,338 ) $ (5,813 ) $ (9,738 ) $ (5,745 ) $ (4,409 ) $ (4,382 ) $ (5,885 ) $ (3,686 ) Basic and diluted net loss per share $ (0.23 ) $ (0.23 ) $ (0.35 ) $ (0.20 ) $ (2.49 ) $ (2.36 ) $ (0.32 ) $ (0.16 ) Shares used to compute basic and diluted net loss per share 23,488 25,015 27,979 28,084 1,773 1,860 18,217 23,375 (1) The first quarter of 2014 included $0.3 million in fair value expense adjustments for the preferred stock warrants classified as liabilities.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	INTERSECT ENT, INC. SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS (in thousands) Fiscal Years Ended December 31, 2015 2014 2013 Allowance for doubtful accounts: Beginning $ — $ — $ — Charges 92 — — Write-offs (6 ) — — Ending $ 86 $ — $ —

Summary of Significant Accoun19

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Basis of Preparation	Basis of Preparation The financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”).
Financial Statements Reclassification	1-for-4 Reverse Stock Split In July 2014, the board of directors and stockholders approved, and the Company filed, an amended and restated certificate of incorporation effecting a 1-for-4 reverse stock split of common stock and all convertible preferred stock. The par value of the common and convertible preferred stock was not adjusted as a result of the reverse stock split. All issued and outstanding common stock, convertible preferred stock, warrants for preferred stock, stock options and per share amounts contained in the financial statements have been retroactively adjusted to reflect this reverse stock split for all periods presented.
Initial Public Offering	Initial Public Offering In July 2014, the Company completed its IPO by issuing 5,750,000 shares of common stock, including 750,000 shares pursuant to the full exercise by the underwriters of their option to purchase additional shares, at an offering price of $11.00 per share, for net proceeds of $55.8 million, after deducting underwriting discounts and commissions of $4.5 million and offering expenses of $3.0 million. In connection with the IPO, the Company’s outstanding shares of convertible preferred stock were automatically converted into 15,703,875 shares of common stock and warrants exercisable for convertible preferred stock were automatically converted into warrants exercisable for 53,357 shares of common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability of $0.4 million to additional paid-in capital.
Follow-on Public Offering	Follow-on Public Offering In June 2015, the Company completed its follow-on public offering by issuing 4,119,300 shares of common stock, including 537,300 shares pursuant to the full exercise by the underwriters of their option to purchase additional shares, at an offering price of $25.00 per share, for net proceeds of approximately $96.4 million, after deducting underwriting discounts and commissions of $6.2 million and offering expenses of $0.4 million.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts and disclosures reported in the financial statements. Management uses significant judgment when making estimates related to its common stock valuation and related stock-based compensation, the valuations of the convertible preferred stock warrant liability, convertible preferred stock financing option, as well as certain accrued liabilities. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid securities, readily convertible to cash, that mature within 90 days or less from the date of purchase to be cash equivalents.
Short-term Investments, Available-for-Sale and Cash, Cash Equivalents	Short-term Investments, Available-for-Sale Short-term investments, which are available-for-sale, represent highly liquid debt instruments with maturities greater than 90 days at date of purchase. Such investments are recorded at fair value and unrealized holding gains and losses are reported as a separate component of accumulated comprehensive income (loss) in stockholders’ equity until realized. The Company reviews its investment portfolio periodically to assess for other-than-temporary impairment. Should the Company determine that any unrealized losses on the investments are other-than-temporary, the amount of that impairment to be recognized in earnings will depend on whether the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current period credit loss. The specific identification method is used to determine the cost of securities disposed of, with realized gains and losses reflected in interest and other income or expense, as appropriate, in the statement of operations. Cash, Cash Equivalents and Short-term Investments The following is a summary of cash, cash equivalents and short-term investments, available-for-sale, by type of instrument measured at fair value on a recurring basis (in thousands): December 31, 2015 2014 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash $ 2,702 $ — $ — $ 2,702 $ 1,971 $ — $ — $ 1,971 Money market funds 26,856 — — 26,856 11,432 — — 11,432 Corporate debt securities — 57,517 — 57,517 — 28,790 — 28,790 Commercial paper — 37,225 — 37,225 — 6,250 — 6,250 $ 29,558 $ 94,742 $ — $ 124,300 $ 13,403 $ 35,040 $ — $ 48,443 Reported as: Cash and cash equivalents $ 34,809 $ 13,403 Short-term investments, available-for-sale 89,491 35,040 $ 124,300 $ 48,443 There were no transfers in and out of Level 1 and Level 2 fair value measurements during the years ended December 31, 2015 and 2014.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company measures certain financial assets and liabilities at fair value on a recurring basis, including cash equivalents, short-term investments, the convertible preferred stock warrant liability and the convertible preferred stock financing option. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. A three-tier fair value hierarchy is established as a basis for considering such assumptions and for inputs used in the valuation methodologies in measuring fair value: Level 1 — Observable inputs such as quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 — Include other inputs that are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuation techniques for which all significant inputs are observable in the market or can be derived from observable market data. Where applicable, these models project future cash flows and discount the future amounts to a present value using market-based observable inputs including interest rate curves, foreign exchange rates, and credit ratings. Level 3 — Unobservable inputs that are supported by little or no market activities, which would require the Company to develop its own assumptions. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.
Convertible Preferred Stock Warrant Liability	Convertible Preferred Stock Warrant Liability The following table sets forth a summary of the changes in the estimated fair value of the Company’s convertible preferred stock warrants, which represent financial instruments with valuations classified as Level 3. When a determination is made to classify a financial instrument within Level 3, the determination is based upon the significance of the unobservable inputs to the overall fair value measurement. However, Level 3 financial instruments typically include, in addition to the unobservable inputs, observable inputs (that is, components that are actively quoted and can be validated to external sources). Accordingly, the expense in the table below includes changes in fair value due in part to observable factors that are part of the Level 3 methodology (in thousands): Fiscal Years Ended 2014 2013 Beginning of the period $ 237 $ 93 Issued — 10 Exercised (29 ) — Reclassified to equity (1) (406 ) — Change in fair value 198 134 End of the period $ — $ 237 (1) In connection with the Company’s IPO in July 2014, warrants for convertible preferred stock were converted to warrants for common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability to additional paid-in capital. The fair value of the convertible preferred stock warrants was determined using the option pricing method, the probability weighted expected return method or Black-Scholes option pricing model using the following assumptions: Fiscal Years Ended 2014 2013 Expected term (years) 2.0 2.0 Expected volatility 46 % 45 % Risk-free interest rate 0.5 % 0.4 % Dividend yield 0.0 % 0.0 % For a warrant classified as a derivative liability, the fair value of that warrant was recorded on the balance sheet at the inception of such classification and adjusted to fair value at each financial reporting date. The changes in the fair value of the warrants were recorded in the statement of operations and comprehensive loss as a component of interest and other income or expense, as appropriate. The Company continued to adjust the carrying value of the convertible preferred stock warrant liability for changes in the fair value of the warrants until the earlier of: the exercise of the warrants, at which time the liability was reclassified to temporary equity; the conversion of the underlying convertible preferred stock into common stock, at which time the liability was reclassified to stockholders’ equity (deficit); or the expiration of the warrant, at which time the entire amount would have been reversed and reflected in the statement of operations and comprehensive loss. In connection with the Company’s IPO in July 2014, the warrants for convertible preferred stock were converted to warrants for common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability of $0.4 million to additional paid-in capital.
Convertible Preferred Stock Financing Option	Convertible Preferred Stock Financing Option For a freestanding option to purchase in a future round of financing, the fair value of that option was recorded on the balance sheet at the inception of such classification and adjusted to fair value at each financial reporting date. The change in the fair value of the convertible preferred stock financing option was recorded in the statement of operations and comprehensive loss as a component of interest and other income or expense, as appropriate. The Company adjusted the carrying value of the convertible preferred stock financing option liability for changes in the fair value of the option and continued to do so until the earlier of when the convertible preferred stock financing option was exercised or expired.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash equivalents, short-term investments and accounts receivable. The Company believes that the credit risk in its accounts receivable is mitigated by its credit evaluation process, relatively short collection terms and dispersion of its customer base. The Company generally does not require collateral and losses on accounts receivable have historically been within management’s expectations. The Company’s investment policy limits investments to certain types of debt securities issued by the U.S. government, its agencies, and institutions with investment-grade credit ratings, as well as corporate debt or commercial paper issued by the highest quality financial and non-financial companies, and places restrictions on maturities and concentration by type and issuer. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash and cash equivalents and issuers of investments to the extent recorded on the balance sheets. However, as of December 31, 2015 and 2014, the Company has limited its credit risk associated with cash, cash equivalents and short-term investments by placing its investments with banks it believes are highly creditworthy and with highly rated investments.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The Company will provide for uncollectible accounts receivable by recording an allowance for doubtful accounts for accounts receivable deemed uncollectible. The Company evaluates the collectability of its accounts receivable based on known collection risks and historical experience. In circumstances where the Company is aware of a specific customer’s inability to meet its financial obligations to the Company (e.g., bankruptcy filings, substantial downgrading of credit ratings), the Company records a specific allowance for bad debts against amounts due to reduce the carrying amount of accounts receivable to the amount it reasonably believes will be collected. If circumstances change, such as higher-than-expected defaults or an unexpected material adverse change in a major customer’s ability to meet its financial obligations, the Company’s estimates of the recoverability of the amounts due could be reduced by a significant amount. Based on the high creditworthiness of the customers that the Company sells to, the Company has experienced no significant collection issues.
Inventory	Inventory Inventory is valued at the lower of cost or market, computed on a first-in, first-out basis, or net realizable value. This requires the Company to make estimates regarding the recoverability of its inventory, including an assessment of excess or obsolete inventory. The Company determines excess and obsolete inventory based on future demand for products within a specified time horizon, generally 12 months, product life cycles and expiration of inventory prior to sale. Any inventory written down creates a new cost basis for the inventory value.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is determined using the straight-line method over the estimated useful lives of the respective assets, generally three to five years. Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated useful lives or the term of the lease. Amortization of assets under capital leases is included in depreciation and amortization expense. Maintenance and repairs are charged to operations as incurred.
Impairment of Long-lived Assets	Impairment of Long-lived Assets Long-lived assets consists primarily of property and equipment and are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require that a long-lived asset be tested for possible impairment, the Company compares the undiscounted cash flows expected to be generated by the asset group to the carrying amount of the asset group. If the carrying amount of the long-lived asset is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying amount exceeds its fair value. The Company determines fair value using the income approach based on the present value of expected future cash flows or other appropriate measures of estimated fair value. The Company’s cash flow assumptions consider historical and forecasted revenue and operating costs and other relevant factors. Since inception, the Company has not recorded impairment charges on long-lived assets.
Revenue Recognition	Revenue Recognition Revenue is derived from the sale of PROPEL and PROPEL mini to hospitals and ambulatory surgery centers in the United States. The Company recognizes revenue when persuasive evidence of an arrangement exists, product delivery has occurred or there is no further obligation, pricing is fixed or determinable and collection is reasonably assured. The Company must make significant assumptions regarding the future collectability of amounts receivable from customers to determine whether revenue recognition criteria have been met. If collectability is not reasonably assured at the time of shipment, the Company defers revenue until such criteria have been met. In general, the Company’s standard terms and conditions of sale do not allow for product returns. The Company expenses shipping and handling costs as incurred and includes them in the cost of sales. In those cases where shipping and handling costs are billed to customers, the Company classifies the amounts billed as a component of revenue.
Cost of Sales	Cost of Sales Cost of sales consists primarily of manufacturing overhead costs, material costs and direct labor. A significant portion of the Company’s cost of sales currently consists of manufacturing overhead costs. These overhead costs include the cost of quality assurance, material procurement, inventory control, facilities, equipment and operations supervision and management. Cost of sales also includes depreciation expense for production equipment and certain direct costs such as shipping costs.
Research and Development	Research and Development Research and development expenses consist primarily of product development, clinical and regulatory affairs, consulting services and other costs associated with products and technologies in development. These expenses include employee compensation, stock-based compensation, supplies, quality assurance and related travel and facility costs. Clinical expenses include clinical trial design, clinical site reimbursement, data management and travel expenses, and the cost of manufacturing products for clinical trials.
Common Stock Valuation and Stock-based Compensation	Common Stock Valuation and Stock-based Compensation The Company maintains a payment equity incentive plans to provide long-term incentives for employees, consultants and members of the board of directors. The plan allows for the issuance of non-statutory and incentive stock options to employees and non-statutory stock options to consultants and non-employee directors. The Company is required to determine the fair value of equity incentive awards and recognize compensation expense for all equity incentive awards made to employees and directors, including employee stock options. Stock-based compensation expense is recognized over the requisite service period in the statements of operations and comprehensive loss and is based on awards ultimately expected to vest, therefore the amount of expense has been reduced for estimated forfeitures. The Company uses the straight-line method for expense attribution, except for awards issued with performance-based conditions which require an accelerated attribution method over the requisite performance and service periods. Under the applicable accounting guidance for equity incentive awards issued to non-employees, the date at which the fair value of such awards is measured is equal to the earlier of: 1) the date at which a commitment for performance by the counterparty to earn the equity instrument is reached; or 2) the date at which the counterparty’s performance is complete. The Company recognizes stock-based compensation expense for the fair value of the vested portion of the non-employee awards in the statements of operations and comprehensive loss. The fair value of options granted to non-employees is remeasured as the options vest. The valuation model used for calculating the fair value of awards for stock-based compensation expense is the Black-Scholes option-pricing model (the “Black-Scholes model”). The Black-Scholes model 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), the volatility of common stock and an assumed risk-free interest rate. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected term of the option. Since stock-based compensation expense is based on awards ultimately expected to vest, potential forfeitures are estimated based on the Company’s historical forfeiture experience and an analysis of similar companies. To the extent actual forfeitures differ from the estimates, the Company records the difference as a cumulative adjustment in the period that the estimates are revised.
Deferred Rent	Deferred Rent Rent expense is recognized on a straight-line basis over the non-cancelable term of the Company’s operating lease and, accordingly, the Company records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. The Company also records lessor-funded lease incentives, such as leasehold improvements, as a deferred rent liability, which is amortized as a reduction of rent expense over the non-cancelable term of its operating lease.
Advertising Expenses	Advertising Expenses The Company expenses the costs of advertising, including promotional expenses, as incurred. Advertising expenses were $0.3 million, $0.1 million and $46,000 during the years ended December 31, 2015, 2014 and 2013, respectively.
Income Taxes	Income Taxes The Company accounts for income taxes under the liability method. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates that will be in effect when the differences are expected to reverse. Valuation allowances against deferred tax assets are established when necessary to reduce deferred tax assets to the amounts expected to be realized. Currently, the Company has recorded a full valuation allowance against its deferred tax assets and there is no provision for income taxes, as the Company has incurred operating losses to date. The Company’s policy is to record interest and penalties expense related to uncertain tax positions as “other expense” in the statement of operations.
Net Loss per Share	Net Loss per Share Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and dilutive potential shares of common stock outstanding during the period. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods as all potentially dilutive shares consisting of convertible preferred stock, stock options and warrants were antidilutive in those periods. The Company allocates no loss to participating securities because the participating securities have no contractual obligation to share in the losses of the Company. The shares of the Company’s convertible preferred stock participate in any dividends declared by the Company and are therefore considered to be participating securities. Net loss per share was determined as follows (in thousands, except per share amounts): Fiscal Years Ended December 31, 2015 2014 2013 Net loss $ (26,634 ) $ (18,362 ) $ (18,369 ) Weighted average common stock outstanding (1) 26,159 11,384 1,461 Net loss per share, basic and diluted (1) $ (1.02 ) $ (1.61 ) $ (12.57 ) (1) In connection with the Company’s IPO in July 2014, the convertible preferred stock outstanding was converted into 15,703,875 shares of common stock on a one-for-one basis. The following potentially dilutive securities outstanding have been excluded from the computations of weighted average shares outstanding because such securities have an antidilutive impact due to losses reported, in common stock equivalent shares (in thousands): Fiscal Years Ended December 31, 2015 2014 2013 Convertible preferred stock outstanding (1) — — 15,701 Convertible preferred stock warrants (1) — — 57 Common stock warrants — 66 — Common stock options 2,946 2,458 1,928 ESPP 252 — — 3,198 2,524 17,686 (1) In connection with the Company’s IPO in July 2014, the convertible preferred stock outstanding was converted into 15,703,875 shares of common stock and the convertible preferred stock warrants were converted into common stock warrants, both on a one-for-one basis.
Comprehensive Loss	Comprehensive Loss Comprehensive loss consists of net loss and changes in unrealized gains and losses on short-term investments, available-for-sale.
Segment, Geographical and Customer Concentration	Segment, Geographical and Customer Concentration The Company has one operating segment. All of the Company’s assets and revenue are based in the U.S. No single customer accounted for more than 10% of its revenue during the years ended December 31, 2015, 2014 and 2013, and no single customer accounted for more than 10% of its accounts receivable at December 31, 2015 and 2014
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date Revenue from Contracts with Customers In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern In June 2014, the FASB issued ASU No. 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period
Series D Convertible Preferred Stock Financing Option [Member]
Convertible Preferred Stock Financing Option	Series D Convertible Preferred Stock Financing Option In February 2013, the Company completed the initial closing of the Series D convertible preferred stock financings. The total net cash proceeds from this initial closing totaled $18.2 million and 2,656,636 shares of Series D convertible preferred stock were issued. In March 2013, the Company completed an additional closing of the Series D convertible preferred stock financings. The total net cash proceeds from this additional closing totaled $2.5 million and 370,129 shares of Series D convertible preferred stock were issued. The March 2013 closing included 72,548 shares purchased by certain employees of the Company for $0.5 million. The Series D convertible preferred stock financing contained a provision that obligated the investors to purchase additional shares (“convertible preferred stock financing option”) at the same price as the initial closing upon notification by the Company that it had achieved an annualized revenue rate of at least $16.0 million over a trailing three-month period. This convertible preferred stock financing option to purchase Series D convertible preferred stock in the future tranche was considered to be a freestanding financial instrument for accounting purposes. Therefore, in February 2013, the Company recorded a financing liability of $0.9 million representing the fair value of this convertible preferred stock financing option at the time of issuance. In October 2013, shortly after achieving the annualized revenue rate, the Company issued the additional 1,369,008 shares of Series D convertible preferred stock to the investors for net proceeds of $9.4 million. Since the convertible preferred stock financing option expired in October 2013 as a result of the issuance of Series D convertible preferred stock, the carrying and fair value of the convertible preferred stock financing option of $1.1 million in October 2013 was reclassified from liability to Series D convertible preferred stock. The Company recorded total charges related to the change in fair value during the year ended December 31, 2013 of $0.2 million related to this financing option liability. The following table sets forth a summary of the changes in the estimated fair value of the Company’s convertible preferred stock financing option, which represents financial instruments with valuations classified as Level 3 (in thousands): Fiscal Year Ended Beginning of the period $ — Issued 885 Exercised (1,097 ) Change in fair value 212 End of the period $ — The fair value of the convertible preferred stock financing liability was determined using the present value methodology with the following assumptions which are categorized as Level 3: February October Total consideration per share $ 1.72 $ 1.72 Additional investment per share 1.72 1.72 Discount rate 20.0 % 20.0 % Probability of achievement 95.0 % 95.0 % Years until milestone achieved 0.5 0.7

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Summary of Cash, Cash Equivalents and Available-for-Sale Investments Measured at Fair Value on Recurring Basis	The following is a summary of cash, cash equivalents and short-term investments, available-for-sale, by type of instrument measured at fair value on a recurring basis (in thousands): December 31, 2015 2014 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash $ 2,702 $ — $ — $ 2,702 $ 1,971 $ — $ — $ 1,971 Money market funds 26,856 — — 26,856 11,432 — — 11,432 Corporate debt securities — 57,517 — 57,517 — 28,790 — 28,790 Commercial paper — 37,225 — 37,225 — 6,250 — 6,250 $ 29,558 $ 94,742 $ — $ 124,300 $ 13,403 $ 35,040 $ — $ 48,443 Reported as: Cash and cash equivalents $ 34,809 $ 13,403 Short-term investments, available-for-sale 89,491 35,040 $ 124,300 $ 48,443
Schedule of Net Loss Per Share	Net loss per share was determined as follows (in thousands, except per share amounts): Fiscal Years Ended December 31, 2015 2014 2013 Net loss $ (26,634 ) $ (18,362 ) $ (18,369 ) Weighted average common stock outstanding (1) 26,159 11,384 1,461 Net loss per share, basic and diluted (1) $ (1.02 ) $ (1.61 ) $ (12.57 ) (1) In connection with the Company’s IPO in July 2014, the convertible preferred stock outstanding was converted into 15,703,875 shares of common stock on a one-for-one basis.
Schedule of Potentially Dilutive Securities Outstanding Excluded from the Computations of Diluted Weighted Average Shares Outstanding	The following potentially dilutive securities outstanding have been excluded from the computations of weighted average shares outstanding because such securities have an antidilutive impact due to losses reported, in common stock equivalent shares (in thousands): Fiscal Years Ended December 31, 2015 2014 2013 Convertible preferred stock outstanding (1) — — 15,701 Convertible preferred stock warrants (1) — — 57 Common stock warrants — 66 — Common stock options 2,946 2,458 1,928 ESPP 252 — — 3,198 2,524 17,686 (1) In connection with the Company’s IPO in July 2014, the convertible preferred stock outstanding was converted into 15,703,875 shares of common stock and the convertible preferred stock warrants were converted into common stock warrants, both on a one-for-one basis.
Series D Convertible Preferred Stock Financing Option [Member]
Schedule of Changes in Estimated Fair Value using Valuations Classified as Level 3	The following table sets forth a summary of the changes in the estimated fair value of the Company’s convertible preferred stock financing option, which represents financial instruments with valuations classified as Level 3 (in thousands): Fiscal Year Ended Beginning of the period $ — Issued 885 Exercised (1,097 ) Change in fair value 212 End of the period $ —
Schedule of Fair Value Assumptions and Methodology	The fair value of the convertible preferred stock financing liability was determined using the present value methodology with the following assumptions which are categorized as Level 3: February October Total consideration per share $ 1.72 $ 1.72 Additional investment per share 1.72 1.72 Discount rate 20.0 % 20.0 % Probability of achievement 95.0 % 95.0 % Years until milestone achieved 0.5 0.7
Convertible Preferred Stock Warrants [Member]
Schedule of Changes in Estimated Fair Value using Valuations Classified as Level 3	The following table sets forth a summary of the changes in the estimated fair value of the Company’s convertible preferred stock warrants, which represent financial instruments with valuations classified as Level 3. When a determination is made to classify a financial instrument within Level 3, the determination is based upon the significance of the unobservable inputs to the overall fair value measurement. However, Level 3 financial instruments typically include, in addition to the unobservable inputs, observable inputs (that is, components that are actively quoted and can be validated to external sources). Accordingly, the expense in the table below includes changes in fair value due in part to observable factors that are part of the Level 3 methodology (in thousands): Fiscal Years Ended 2014 2013 Beginning of the period $ 237 $ 93 Issued — 10 Exercised (29 ) — Reclassified to equity (1) (406 ) — Change in fair value 198 134 End of the period $ — $ 237 (1) In connection with the Company’s IPO in July 2014, warrants for convertible preferred stock were converted to warrants for common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability to additional paid-in capital.
Schedule of Fair Value Assumptions and Methodology	The fair value of the convertible preferred stock warrants was determined using the option pricing method, the probability weighted expected return method or Black-Scholes option pricing model using the following assumptions: Fiscal Years Ended 2014 2013 Expected term (years) 2.0 2.0 Expected volatility 46 % 45 % Risk-free interest rate 0.5 % 0.4 % Dividend yield 0.0 % 0.0 %

Composition of Certain Financ21

Composition of Certain Financial Statement Items (Tables)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Accounts Receivable	Accounts Receivable (in thousands): December 31, 2015 2014 Accounts receivable $ 11,554 $ 8,337 Allowance for doubtful accounts (86 ) — $ 11,468 $ 8,337
Components of Inventory	Inventory (in thousands): December 31, 2015 2014 Raw materials $ 911 $ 761 Work-in-process 187 141 Finished goods 2,851 1,645 $ 3,949 $ 2,547
Property and Equipment	Property and Equipment (in thousands): December 31, 2015 2014 Computer equipment and software $ 632 $ 546 Furniture and office equipment 417 158 Laboratory equipment 3,191 2,276 Leasehold improvements 1,256 128 5,496 3,108 Less: accumulated depreciation and amortization (2,313 ) (1,634 ) $ 3,183 $ 1,474

Cash, Cash Equivalents and Sh22

Cash, Cash Equivalents and Short-term Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Cash and Cash Equivalents [Abstract]
Summary of Cash, Cash Equivalents and Available-for-Sale Investments by Type of Instrument	The following is a summary of cash, cash equivalents and short-term investments, available-for-sale, by type of instrument (in thousands): December 31, 2015 2014 Amortized Cost Gross Unrealized Estimated Fair Value Amortized Cost Gross Unrealized Estimated Fair Value Gains Losses Gains Losses Cash $ 2,702 $ — $ — $ 2,702 $ 1,971 $ — $ — $ 1,971 Money market funds 26,856 — — 26,856 11,432 — — 11,432 Corporate debt securities 57,546 — (29 ) 57,517 28,797 3 (10 ) 28,790 Commercial paper 37,188 37 — 37,225 6,243 7 — 6,250 $ 124,292 $ 37 $ (29 ) $ 124,300 $ 48,443 $ 10 $ (10 ) $ 48,443 Reported as: Cash and cash equivalents $ 34,809 $ 13,403 Short-term investments, available-for-sale 89,491 35,040 $ 124,300 $ 48,443

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Summary of Stock Option Activity	A summary of the Company’s stock option activity and related information is as follows (in thousands, except price data): Fiscal Years Ended December 31, 2015 2014 2013 Options Price Options Price Options Price Outstanding, beginning of period 2,458 $ 4.84 1,928 $ 1.08 1,594 $ 0.88 Granted 1,181 22.90 819 12.88 1,033 1.20 Granted - below fair market value — — — — 94 1.32 Exercised (560 ) 1.59 (163 ) 1.42 (740 ) 0.84 Forfeited (85 ) 20.27 (126 ) 3.86 (53 ) 1.08 Expired (48 ) 5.58 — — — — Outstanding, end of period 2,946 12.24 2,458 4.84 1,928 1.08 Vested and expected to vest 2,853 11.84 2,338 4.67 1,752 1.08 Exercisable 1,547 6.35 1,612 2.66 1,314 1.00

Stock-Based Compensation Expe24

Stock-Based Compensation Expense (Tables)	12 Months Ended
	Dec. 31, 2015
2014 Equity Incentive Plan [Member]
Summary of Stock Based Compensation Recognized	Total stock-based compensation expense recognized is as follows (in thousands): Fiscal Years Ended December 31, 2015 2014 2013 Cost of sales $ 280 $ 49 $ 21 Selling, general and administrative 3,837 1,361 273 Research and development 747 140 88 $ 4,864 $ 1,550 $ 382
Summary of Weighted Average Assumptions Used to Estimate Options Using Black-Scholes Model	The fair value of options granted to employees or directors during the periods presented below were estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Fiscal Years Ended 2015 2014 2013 Expected term (years) 6.0 6.0 6.0 Expected volatility 48 % 56 % 67 % Risk-free interest rate 1.6 % 1.9 % 1.6 % Dividend yield 0.0 % 0.0 % 0.0 % Weighted average fair value $ 10.66 $ 6.80 $ 0.96
2014 Employee Stock Purchase Plan [Member]
Summary of Weighted Average Assumptions Used to Estimate Options Using Black-Scholes Model	The fair value of options granted under the 2014 ESPP to employees was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Fiscal Year Ended Expected term (years) 1.3 Expected volatility 38 % Risk-free interest rate 0.4 % Dividend yield 0.0 % Weighted average fair value $ 7.29

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Summary of Future Minimum Annual Operating Lease Payments	Future minimum annual operating lease payments are as follows (in thousands): Fiscal Years Ending December 31, December 31, 2016 $ 1,494 2017 1,536 2018 1,580 2019 1,625 2020 685 $ 6,920

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Federal Statutory Rate to Loss Before Taxes Reconciles to Provision for Income Taxes	The amount computed by applying the federal statutory rate to loss before taxes reconciles to the provision for income taxes is as follows (in thousands): Fiscal Years Ended December 31, 2015 2014 2013 Tax at federal statutory rate $ (9,056 ) $ (6,243 ) $ (6,245 ) State tax, net of federal benefit (589 ) (1,264 ) (826 ) Permanent items 675 515 368 R&D tax credit (559 ) (315 ) (584 ) Other — 12 (2 ) Change in valuation allowance 9,529 7,295 7,289 $ — $ — $ —
Schedule of Significant Components of Net Deferred Tax Assets	Significant components of net deferred tax assets are as follows (in thousands): December 31, 2015 2014 Deferred tax assets: Net operating losses $ 40,136 $ 33,912 R&D tax credit 3,691 2,888 Accruals and other 5,296 2,465 49,123 39,265 Deferred tax liabilities: Depreciation and amortization (391 ) (62 ) (391 ) (62 ) Net deferred tax asset: 48,732 39,203 Valuation allowance (48,732 ) (39,203 ) $ — $ —
Schedule of Reconciliation of Change in Unrecognized Tax Benefit	A reconciliation of the change in the unrecognized tax benefit during the year is as follows (in thousands): December 31, 2015 2014 2013 Beginning of year $ 861 $ 715 $ 505 Additions for tax positions related to: Current year 227 140 210 Prior years 6 6 — End of year $ 1,094 $ 861 $ 715

Supplemental Quarterly Financ27

Supplemental Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information of Statements of Operations	The following table sets forth unaudited statements of operations data for each of the Company’s last eight quarters. This quarterly information is unaudited and has been prepared on the same basis as the annual financial statements. In the Company’s opinion, this quarterly information reflects all adjustments necessary for a fair presentation of the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period. Fiscal Years Ended December 31, 2015 2014 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Revenue $ 13,372 $ 15,198 $ 14,232 $ 18,791 $ 7,497 $ 8,565 $ 9,100 $ 13,425 Cost of sales 2,792 2,904 2,877 3,715 2,360 2,320 2,576 2,967 Gross profit 10,580 12,294 11,355 15,076 5,137 6,245 6,524 10,458 Gross margin 79 % 81 % 80 % 80 % 69 % 73 % 72 % 78 % Operating expenses: Sales, general and administrative 12,620 14,117 16,420 16,480 6,658 8,291 9,667 11,495 Research and development 3,326 4,038 4,799 4,445 2,577 2,377 2,758 2,619 Total operating expenses 15,946 18,155 21,219 20,925 9,235 10,668 12,425 14,114 Loss from operations (5,366 ) (5,861 ) (9,864 ) (5,849 ) (4,098 ) (4,423 ) (5,901 ) (3,656 ) Interest and other income (expense), net (1) 28 48 126 104 (311 ) 41 16 (30 ) Net loss $ (5,338 ) $ (5,813 ) $ (9,738 ) $ (5,745 ) $ (4,409 ) $ (4,382 ) $ (5,885 ) $ (3,686 ) Basic and diluted net loss per share $ (0.23 ) $ (0.23 ) $ (0.35 ) $ (0.20 ) $ (2.49 ) $ (2.36 ) $ (0.32 ) $ (0.16 ) Shares used to compute basic and diluted net loss per share 23,488 25,015 27,979 28,084 1,773 1,860 18,217 23,375 (1) The first quarter of 2014 included $0.3 million in fair value expense adjustments for the preferred stock warrants classified as liabilities.

Organization - Additional Infor

Organization - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash, cash equivalents and short-term investments	$ 124,300
Accumulated deficit	$ (123,255)	$ (96,621)

Summary of Significant Accoun29

Summary of Significant Accounting Policies - Additional Information (Detail)	1 Months Ended						12 Months Ended
	Jun. 30, 2015USD ($)$ / sharesshares	Jul. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)	Oct. 31, 2013USD ($)shares	Mar. 31, 2013USD ($)shares	Feb. 28, 2013USD ($)shares	Dec. 31, 2015USD ($)CustomerSegments	Dec. 31, 2014USD ($)Customershares	Dec. 31, 2013USD ($)Customer
Subsidiary, Sale of Stock [Line Items]
Reverse stock split, ratio		0.25
Reclassification of redeemable convertible preferred stock warrant liability to additional paid-in capital		$ 400,000						$ 406,000
Transfer of assets from level 1 to level 2							$ 0	0
Transfer of liabilities from level 1 to level 2							0	0
Transfer of assets from level 2 to level 1							0	0
Transfer of liabilities from level 2 to level 1							0	0
Net proceeds from convertible preferred stock financings									$ 30,146,000
Advertising expenses							300,000	$ 100,000	$ 46,000
Loss allocated to participating securities							0
Contractual obligation							$ 0
Number of operating segment | Segments							1
Revenue [Member] | Customer Concentration Risk [Member]
Subsidiary, Sale of Stock [Line Items]
Number of customer accounted for more than 10% | Customer							0	0	0
Concentration risk, percentage							10.00%	10.00%	10.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Subsidiary, Sale of Stock [Line Items]
Number of customer accounted for more than 10% | Customer							0	0
Concentration risk, percentage							10.00%	10.00%
Leasehold Improvements [Member]
Subsidiary, Sale of Stock [Line Items]
Estimated useful lives of lease							Straight-line basis over the shorter of their estimated useful lives or the term of the lease.
Minimum [Member]
Subsidiary, Sale of Stock [Line Items]
Estimated useful life of property and equipment							3 years
Maximum [Member]
Subsidiary, Sale of Stock [Line Items]
Estimated useful life of property and equipment							5 years
Private Placement [Member] | Series D Convertible Preferred Stock Financing Option [Member] | Convertible Preferred Stock Financing Option [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares issued | shares				1,369,008	370,129	2,656,636
Net proceeds from public offering					$ 2,500,000	$ 18,200,000
Annualized revenue rate over a trailing three month period							$ 16,000,000
Financing liability				$ 1,100,000		$ 900,000
Net proceeds from convertible preferred stock financings				$ 9,400,000
Change in fair value charges			$ 200,000
Certain Employee [Member] | Series D Convertible Preferred Stock Financing Option [Member] | Convertible Preferred Stock Financing Option [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares issued | shares					72,548
Net proceeds from public offering					$ 500,000
Common Stock [Member]
Subsidiary, Sale of Stock [Line Items]
Reverse stock split							1-for-4 reverse stock split
Convertible preferred stock converted into shares of common stock | shares		15,703,875						15,704,000
Common Stock [Member] | Initial Public Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares issued | shares		5,750,000
Common stock issued during period, price per share | $ / shares		$ 11
Net proceeds from public offering		$ 55,800,000
Underwriting discounts and commissions		4,500,000
Public offering, expenses		$ 3,000,000
Convertible preferred stock converted into shares of common stock | shares		15,703,875
Warrants exercisable for common stock shares | shares		53,357
Reclassification of redeemable convertible preferred stock warrant liability to additional paid-in capital		$ 400,000
Common Stock [Member] | Over-Allotment Option [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares issued | shares	537,300	750,000
Common Stock [Member] | Follow-on Public Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Number of shares issued | shares	4,119,300
Common stock issued during period, price per share | $ / shares	$ 25
Net proceeds from public offering	$ 96,400,000
Underwriting discounts and commissions	6,200,000
Public offering, expenses	$ 400,000

Summary of Significant Accoun30

Summary of Significant Accounting Policies - Summary of Cash, Cash Equivalents and Short-Term Investments, Available-for-Sale, by Type of Instrument (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Investment [Line Items]
Cash and cash equivalents	$ 34,809	$ 13,403	$ 12,294	$ 2,060
Cash and cash equivalents and short-term investments, available-for-sale	124,300
Fair Value on Recurring Basis [Member]
Net Investment [Line Items]
Cash and cash equivalents	34,809	13,403
Short-term investments, available-for-sale	89,491	35,040
Cash and cash equivalents and short-term investments, available-for-sale	124,300	48,443
Fair Value on Recurring Basis [Member] | Cash [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	2,702	1,971
Fair Value on Recurring Basis [Member] | Money Market Funds [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	26,856	11,432
Fair Value on Recurring Basis [Member] | Corporate Debt Securities [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	57,517	28,790
Fair Value on Recurring Basis [Member] | Commercial Paper [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	37,225	6,250
Level 1 [Member] | Fair Value on Recurring Basis [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	29,558	13,403
Level 1 [Member] | Fair Value on Recurring Basis [Member] | Cash [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	2,702	1,971
Level 1 [Member] | Fair Value on Recurring Basis [Member] | Money Market Funds [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	26,856	11,432
Level 2 [Member] | Fair Value on Recurring Basis [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	94,742	35,040
Level 2 [Member] | Fair Value on Recurring Basis [Member] | Corporate Debt Securities [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	57,517	28,790
Level 2 [Member] | Fair Value on Recurring Basis [Member] | Commercial Paper [Member]
Net Investment [Line Items]
Cash and cash equivalents and short-term investments, available-for-sale	$ 37,225	$ 6,250

Summary of Significant Accoun31

Summary of Significant Accounting Policies - Schedule of Changes in Estimated Fair Value using Valuations Classified as Level 3 - Convertible Preferred Stock Warrant Liability (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Class of Warrant or Right [Line Items]
Reclassified to equity	$ (400)	$ (406)
Change in fair value		198	$ 134
Convertible Preferred Stock Warrants [Member] | Level 3 [Member]
Class of Warrant or Right [Line Items]
Beginning of the period		237	93
Issued			10
Exercised		(29)
Reclassified to equity		(406)
Change in fair value		$ 198	134
End of the period			$ 237

Summary of Significant Accoun32

Summary of Significant Accounting Policies - Summary of Weighted Average Assumptions Used to Estimate Options Using Black-Scholes Model (Detail) - Convertible Preferred Stock Warrants [Member]	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Expected term (years)	2 years	2 years
Expected volatility	46.00%	45.00%
Risk-free interest rate	0.50%	0.40%
Dividend yield	0.00%	0.00%

Summary of Significant Accoun33

Summary of Significant Accounting Policies - Schedule of Changes in Estimated Fair Value using Valuations Classified as Level 3 - Convertible Preferred Stock Financing Option (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2013USD ($)
Fair Value Disclosures [Abstract]
Beginning of the period	$ 0
Issued	885
Exercised	(1,097)
Change in fair value	212
End of the period	$ 0

Summary of Significant Accoun34

Summary of Significant Accounting Policies - Schedule of Fair Value Assumptions and Methodology (Detail) - Series D Convertible Preferred Stock Financing Option [Member] - $ / shares	1 Months Ended
	Oct. 31, 2013	Feb. 28, 2013
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total consideration per share	$ 1.72	$ 1.72
Additional investment per share	$ 1.72	$ 1.72
Discount rate	20.00%	20.00%
Probability of achievement	95.00%	95.00%
Years until milestone achieved	8 months 12 days	6 months

Summary of Significant Accoun35

Summary of Significant Accounting Policies - Schedule of Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net loss	$ (5,745)	$ (9,738)	$ (5,813)	$ (5,338)	$ (3,686)	$ (5,885)	$ (4,382)	$ (4,409)	$ (26,634)	$ (18,362)	$ (18,369)
Weighted average common stock outstanding	28,084	27,979	25,015	23,488	23,375	18,217	1,860	1,773	26,159	11,384	1,461
Net loss per share, basic and diluted	$ (0.20)	$ (0.35)	$ (0.23)	$ (0.23)	$ (0.16)	$ (0.32)	$ (2.36)	$ (2.49)	$ (1.02)	$ (1.61)	$ (12.57)

Summary of Significant Accoun36

Summary of Significant Accounting Policies - Schedule of Net Loss Per Share (Parenthetical) (Detail) - Common Stock [Member] - shares	1 Months Ended	12 Months Ended
	Jul. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Convertible preferred stock was converted to common stock		One-for-one
Conversion of convertible preferred stock to common stock, Shares	15,703,875		15,704,000

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Outstanding Excluded from the Computations of Diluted Weighted Average Shares Outstanding (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares outstanding	3,198	2,524	17,686
2014 Employee Stock Purchase Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares outstanding	252
Common Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares outstanding	2,946	2,458	1,928
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares outstanding			15,701
Convertible Preferred Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares outstanding			57
Common Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted average shares outstanding		66

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Outstanding Excluded from the Computations of Diluted Weighted Average Shares Outstanding (Parenthetical) (Detail) - Common Stock [Member] - shares	1 Months Ended	12 Months Ended
	Jul. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible preferred stock was converted to common stock		One-for-one
Convertible preferred stock was converted into common stock	15,703,875		15,704,000

Composition of Certain Financ39

Composition of Certain Financial Statement Items - Accounts Receivable (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Accounts receivable	$ 11,554	$ 8,337
Allowance for doubtful accounts	(86)
Accounts receivable, net	$ 11,468	$ 8,337

Composition of Certain Financ40

Composition of Certain Financial Statement Items - Components of Inventory (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials	$ 911	$ 761
Work-in-process	187	141
Finished goods	2,851	1,645
Inventory, net	$ 3,949	$ 2,547

Composition of Certain Financ41

Composition of Certain Financial Statement Items - Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Plant and equipment, gross	$ 5,496	$ 3,108
Less: accumulated depreciation and amortization	(2,313)	(1,634)
Plant and equipment, net	3,183	1,474
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Plant and equipment, gross	632	546
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Plant and equipment, gross	417	158
Equipment [Member]
Property, Plant and Equipment [Line Items]
Plant and equipment, gross	3,191	2,276
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Plant and equipment, gross	$ 1,256	$ 128

Cash, Cash Equivalents and Sh42

Cash, Cash Equivalents and Short-term Investments - Summary of Cash, Cash Equivalents and Available-for-Sale Investments by Type of Instrument (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Net Investment [Line Items]
Cash, cash equivalents and available-for-sale investments, Amortized Cost	$ 124,292	$ 48,443
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Gains	37	10
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Losses	(29)	(10)
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	124,300	48,443
Cash and Cash Equivalents [Member]
Net Investment [Line Items]
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	34,809	13,403
Short-term investments, available-for-sale [Member]
Net Investment [Line Items]
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	89,491	35,040
Cash [Member]
Net Investment [Line Items]
Cash, cash equivalents and available-for-sale investments, Amortized Cost	2,702	1,971
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	2,702	1,971
Money Market Funds [Member]
Net Investment [Line Items]
Cash, cash equivalents and available-for-sale investments, Amortized Cost	26,856	11,432
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	26,856	11,432
Corporate Debt Securities [Member]
Net Investment [Line Items]
Cash, cash equivalents and available-for-sale investments, Amortized Cost	57,546	28,797
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Gains		3
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Losses	(29)	(10)
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	57,517	28,790
Commercial Paper [Member]
Net Investment [Line Items]
Cash, cash equivalents and available-for-sale investments, Amortized Cost	37,188	6,243
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Gains	37	7
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	$ 37,225	$ 6,250

Cash, Cash Equivalents and Sh43

Cash, Cash Equivalents and Short-term Investments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investments Schedule [Abstract]
Investments with a maturity of greater than one year	$ 0	$ 0
Other-than-temporary impairment charges	$ 0	$ 0	$ 0

Equipment Loans - Additional In

Equipment Loans - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2014	Aug. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Capital lease obligation						$ 100
Repayments related to capital lease financing	$ 59			$ 87	$ 18
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Interest rate	14.88%
Frequency of monthly payments			38-month
Loans Payable [Member] | Equipment Loan [Member]
Debt Instrument [Line Items]
Aggregate principal amount under loan facility							$ 2,000
Interest rate		5.10%
Repayment of equipment loan		$ 900
Frequency of monthly payments			36-month

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands

Jan. 01, 2015shares

Jul. 23, 2014shares

Jul. 31, 2014USD ($)

Jan. 31, 2013$ / sharesshares

Mar. 31, 2009Patents

Dec. 31, 2015USD ($)shares

Dec. 31, 2014USD ($)shares

Dec. 31, 2013USD ($)shares

May. 31, 2015$ / sharesshares

Feb. 28, 2015shares

Jan. 31, 2015shares

Mar. 31, 2014shares

Dec. 31, 2012shares

Class of Stock [Line Items]

Options outstanding

2,946,000

2,458,000

1,928,000

1,594,000

Aggregate pre-tax intrinsic value of options outstanding and exercisable | $

$ 25,200

Aggregate pre-tax intrinsic value of options outstanding | $

31,500

Aggregate pre-tax intrinsic value of options exercised | $

$ 12,700

$ 1,500

$ 300

Weighted-average remaining contractual term of options outstanding

8 years 1 month 6 days

Weighted-average remaining contractual term of options exercisable

7 years 4 months 24 days

Warrants exercise price per share | $ / shares

$ 3.68

Number of irrigation tool patents purchased | Patents

3

Conversion of convertible preferred stock to common stock, Value | $

90,789

Reclassification of redeemable convertible preferred stock warrant liability to additional paid-in capital | $

$ 400

$ 406

Net common stock shares issued

28,159,000

23,379,000

Net preferred stock shares issued

0

0

Number of shares of Series A convertible preferred stock exercised through exercise of warrants

22,418

Equipment Loan Warrant [Member]

Class of Stock [Line Items]

Warrants exercisable for common stock shares

4,076

Shares withheld for exercise price

1,645

Net preferred stock shares issued

2,431

Venture Loan [Member]

Class of Stock [Line Items]

Warrants exercisable for common stock shares

47,554

Shares withheld for exercise price

7,593

Net common stock shares issued

39,961

Loan Origination Commitments [Member]

Class of Stock [Line Items]

Warrants exercisable for common stock shares

5,803

Shares withheld for exercise price

1,779

Net common stock shares issued

4,024

Warrant [Member]

Class of Stock [Line Items]

Warrants exercisable for common stock shares

43,750

Warrants exercise price per share | $ / shares

$ 1

Convertible Preferred Stock [Member]

Class of Stock [Line Items]

Conversion of convertible preferred stock to common stock, Shares

15,703,875

Conversion of convertible preferred stock to common stock, Value | $

$ 90,800

2014 Employee Stock Purchase Plan [Member]

Class of Stock [Line Items]

Shares authorized for future issuance

496,092

Shares Issued

53,242

2014 Equity Incentive Plan [Member]

Class of Stock [Line Items]

Percentage of shares outstanding

3.00%

Common Stock, Capital Shares Reserved for Future Issuance, increase during period

701,328

Shares reserved for issuance

5,451,328

4,750,000

Maximum number of shares to be issued

10,000,000

Options granted description

Options granted to a 10% stockholder shall be at no less than 110% of the fair value and ISO stock option grants to such 10% stockholders expire five years from the date of grant.

2014 Equity Incentive Plan [Member] | Incentive Stock Option [Member]

Class of Stock [Line Items]

Price of options granted, percentage

100.00%

Expiry period of options granted

10 years

ISOs vested , description

ISOs granted under the 2014 Plan generally vest 25% after the completion of 12 months of service and the balance vests in equal monthly installments over the next 36 months of service and expire 10 years from the grant date, unless subject to provisions regarding 10% stockholders. NSOs vest per the specific agreement and expire 10 years from the date of grant.

2014 Equity Incentive Plan [Member] | 10% Stockholders [Member]

Class of Stock [Line Items]

Expiry period of options granted

5 years

2013 Equity Incentive Plan [Member]

Class of Stock [Line Items]

Options issued, vested

10,000

0

Options outstanding

500,000

Stockholder's Equity - Summary

Stockholder's Equity - Summary of Stock Option Activity (Detail) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equity [Abstract]
Options outstanding, beginning of period	2,458	1,928	1,594
Options granted	1,181	819	1,033
Options granted - below fair market value			94
Options exercised	(560)	(163)	(740)
Options forfeited	(85)	(126)	(53)
Options expired	(48)
Options outstanding, end of period	2,946	2,458	1,928
Options vested and expected to vest	2,853	2,338	1,752
Options exercisable	1,547	1,612	1,314
Options price, outstanding, beginning of period	$ 4.84	$ 1.08	$ 0.88
Options price, granted	22.90	12.88	1.20
Options price, granted - below fair market value			1.32
Options price, exercised	1.59	1.42	0.84
Options price, forfeited	20.27	3.86	1.08
Option price, expired	5.58
Options price, outstanding, end of period	12.24	4.84	1.08
Options price, vested and expected to vest	11.84	4.67	1.08
Options price, exercisable	$ 6.35	$ 2.66	$ 1

Stock-Based Compensation Expe47

Stock-Based Compensation Expense - Summary of Stock Based Compensation Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 4,864	$ 1,550	$ 382
Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	280	49	21
Selling, General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,837	1,361	273
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 747	$ 140	$ 88

Stock-Based Compensation Expe48

Stock-Based Compensation Expense - Additional Information (Detail) - USD ($) shares in Millions	1 Months Ended		12 Months Ended
	Jun. 30, 2014	Apr. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned stock-based compensation			$ 13,200,000
Weighted average period for unearned stock-based compensation to be recognized			2 years 9 months 18 days
Issuance of common stock upon exercise of stock options			$ 909,000	$ 244,000	$ 365,000
Conversion of options to grant restricted stock		0.6
Vesting period			4 years
Incremental cost of modification		$ 300,000
Incremental cost recognized			$ 50,000	$ 200,000	$ 50,000
Unamortized modification cost related to vested options	$ 200,000
Remaining unamortized cost yet to be amortized	$ 100,000
Promissory Notes [Member] | President And Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock upon exercise of stock options		$ 500,000
Minimum [Member] | Promissory Notes [Member] | President And Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Liquidation event threshold representing total proceeds payable to the Company			$ 200,000,000

Stock-Based Compensation Expe49

Stock-Based Compensation Expense - Summary of Weighted Average Assumptions Used to Estimate Options Using Black-Scholes Model (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
2014 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (years)	1 year 3 months 18 days
Expected volatility	38.00%
Risk-free interest rate	0.40%
Dividend yield	0.00%
Weighted average fair value	$ 7.29
2014 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (years)	6 years	6 years	6 years
Expected volatility	48.00%	56.00%	67.00%
Risk-free interest rate	1.60%	1.90%	1.60%
Dividend yield	0.00%	0.00%	0.00%
Weighted average fair value	$ 10.66	$ 6.80	$ 0.96

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)ft²	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Commitments and Contingencies Disclosure [Abstract]
Operating lease, Date	2012-03
Renewal provision allowing the Company to extend lease, percentage	95.00%
Lease agreement description	Rental payments are charged to expense on a straight-line basis over the period of the lease. The lease agreement requires the Company to pay executory costs such as real estate taxes, insurance and repairs, and includes a renewal provision allowing the Company to extend this lease for an additional three years at 95% of the then-current fair market rental rate.
Additional area under operating lease agreement | ft²	17,900
Total area under operating lease agreement | ft²	50,400
Operating lease , expiration date	May 31, 2020
Building improvements payable by the lessor	$ 1
Rent expense	1.9	$ 1.3	$ 1.4
Commitments to suppliers for purchases	$ 1.9

Commitments and Contingencies51

Commitments and Contingencies - Summary of Future Minimum Annual Operating Lease Payments (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,016	$ 1,494
2,017	1,536
2,018	1,580
2,019	1,625
2,020	685
Total	$ 6,920

Employee Retirement Plan - Addi

Employee Retirement Plan - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2007	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Maximum annual contribution per employee, percent	100.00%
Contributions, annual vesting percentage	25.00%
Contributions, vesting period	4 years
Matching contribution description		Company may also make matching contributions of up to 3% of an employee's eligible compensation.
Profit sharing or matching contribution by employer		$ 0.2
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching contribution percentage	3.00%

Income Taxes - Schedule of Fede

Income Taxes - Schedule of Federal Statutory Rate to Loss Before Taxes Reconciles to Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax at federal statutory rate	$ (9,056)	$ (6,243)	$ (6,245)
State tax, net of federal benefit	(589)	(1,264)	(826)
Permanent items	675	515	368
R&D tax credit	(559)	(315)	(584)
Other		12	(2)
Change in valuation allowance	9,529	7,295	7,289
Provision for income taxes	$ 0	$ 0	$ 0

Income Taxes - Schedule of Sign

Income Taxes - Schedule of Significant Components of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Net operating losses	$ 40,136	$ 33,912
R&D tax credit	3,691	2,888
Accruals and other	5,296	2,465
Gross deferred tax assets	49,123	39,265
Deferred tax liabilities:
Depreciation and amortization	(391)	(62)
Deferred tax liabilities, gross	(391)	(62)
Net deferred tax asset:	48,732	39,203
Valuation allowance	(48,732)	(39,203)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Contingency [Line Items]
Increase in valuation allowance	$ 9,500,000	$ 7,300,000
Net operating loss carryforwards, federal	112,400,000
Net operating loss carryforwards, state	55,900,000
Research and development tax credits	3,691,000	2,888,000
Unrecognized tax benefit	1,094,000	$ 861,000	$ 715,000	$ 505,000
Interest or penalties accrued on unrecognized tax benefits	$ 0
Significant change to unrecognized tax benefits	The Company does not expect a significant change to its unrecognized tax benefits over the next twelve months. The unrecognized tax benefits may increase or change during the next twelve months for items that arise in the ordinary course of business.
Tax years beginning, description	Tax years beginning in 2004 through 2015 remain open to examination by the major taxing authorities to which the Company is subject to.
Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax examination year	2,004
Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax examination year	2,015
Federal [Member]
Income Tax Contingency [Line Items]
Research and development tax credits	$ 3,000,000
Operating loss carryforwards, expiration year	2,023
Research and development tax credits, expiration year	2,023
State [Member]
Income Tax Contingency [Line Items]
Research and development tax credits	$ 2,500,000
Operating loss carryforwards, expiration year	2,015

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Change in Unrecognized Tax Benefit (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Beginning of year	$ 861	$ 715	$ 505
Additions for tax positions related to:
Current year	227	140	210
Prior years	6	6
End of year	$ 1,094	$ 861	$ 715

Supplemental Quarterly Financ57

Supplemental Quarterly Financial Information - Quarterly Financial Information of Statements of Operations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 18,791	$ 14,232	$ 15,198	$ 13,372	$ 13,425	$ 9,100	$ 8,565	$ 7,497	$ 61,593	$ 38,587	$ 17,931
Cost of sales	3,715	2,877	2,904	2,792	2,967	2,576	2,320	2,360	12,288	10,223	8,150
Gross profit	$ 15,076	$ 11,355	$ 12,294	$ 10,580	$ 10,458	$ 6,524	$ 6,245	$ 5,137	49,305	28,364	9,781
Gross margin	80.00%	80.00%	81.00%	79.00%	78.00%	72.00%	73.00%	69.00%
Operating expenses:
Sales, general and administrative	$ 16,480	$ 16,420	$ 14,117	$ 12,620	$ 11,495	$ 9,667	$ 8,291	$ 6,658	59,637	36,111	18,229
Research and development	4,445	4,799	4,038	3,326	2,619	2,758	2,377	2,577	16,608	10,331	9,518
Total operating expenses	20,925	21,219	18,155	15,946	14,114	12,425	10,668	9,235	76,245	46,442	27,747
Loss from operations	(5,849)	(9,864)	(5,861)	(5,366)	(3,656)	(5,901)	(4,423)	(4,098)	(26,940)	(18,078)	(17,966)
Interest and other income (expense), net	104	126	48	28	(30)	16	41	(311)
Net loss	$ (5,745)	$ (9,738)	$ (5,813)	$ (5,338)	$ (3,686)	$ (5,885)	$ (4,382)	$ (4,409)	$ (26,634)	$ (18,362)	$ (18,369)
Basic and diluted net loss per share	$ (0.20)	$ (0.35)	$ (0.23)	$ (0.23)	$ (0.16)	$ (0.32)	$ (2.36)	$ (2.49)	$ (1.02)	$ (1.61)	$ (12.57)
Shares used to compute basic and diluted net loss per share	28,084	27,979	25,015	23,488	23,375	18,217	1,860	1,773	26,159	11,384	1,461

Supplemental Quarterly Financ58

Supplemental Quarterly Financial Information - Quarterly Financial Information of Statements of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Effect Of First Quarter Events [Line Items]
Fair value expense adjustments for the preferred stock warrants		$ 198	$ 134
Convertible Preferred Stock [Member]
Effect Of First Quarter Events [Line Items]
Fair value expense adjustments for the preferred stock warrants	$ 300

Schedule II - Valuation and Q59

Schedule II - Valuation and Qualifying Accounts (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Allowance for doubtful accounts
Charges	$ 92
Write-offs	(6)
Ending	$ 86