Intersect ENT (XENT) 10-Q 10 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'XENT	'
Entity Registrant Name	'Intersect ENT, Inc.	'
Entity Central Index Key	'0001271214	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	23,376,751

Condensed_Balance_Sheets

Condensed Balance Sheets (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$19,233	$12,294	[1]
Short-term investments	34,384	'
Accounts receivable, net	4,934	4,200	[1]
Inventory	2,680	2,197	[1]
Restricted cash	'	62	[1]
Prepaid expenses and other current assets	1,188	449	[1]
Total current assets	62,419	19,202	[1]
Property and equipment, net	1,611	1,707	[1]
Other non-current assets	111	126	[1]
Total assets	64,141	21,035	[1]
Current liabilities:	'	'
Accounts payable	2,088	1,451	[1]
Accrued compensation	4,219	2,955	[1]
Equipment loans - current portion	35	696	[1]
Convertible preferred stock warrant liability	'	237	[1]
Other current liabilities	832	745	[1]
Total current liabilities	7,174	6,084	[1]
Equipment loans - non-current portion	30	756	[1]
Deferred rent	'	52	[1]
Total liabilities	7,204	6,892	[1]
Commitments and contingencies (note 14)	'	'	[1]
Convertible preferred stock issuable in series, $0.001 par value; Authorized shares: none at September 30, 2014 and 15,907 at December 31, 2013; Issued and outstanding shares: none at September 30, 2014 and 15,701 at December 31, 2013	'	90,760	[1]
Preferred stock, $0.001 par value; Authorized shares: 10,000 at September 30, 2014 and none at December 31, 2013; Issued and outstanding shares: none	'	'	[1]
Common stock, $0.001 par value; Authorized shares: 150,000 at September 30, 2014 and December 31, 2013; Issued and outstanding shares: 23,368 at September 30, 2014 and 1,761 at December 31, 2013	23	2	[1]
Additional paid-in capital	149,843	1,859	[1]
Note receivable from related party	'	-219	[1]
Accumulated other comprehensive income	6	'
Accumulated deficit	-92,935	-78,259	[1]
Total stockholders' equity (deficit)	56,937	-76,617	[1]
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$64,141	$21,035	[1]
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Condensed_Balance_Sheets_Paren

Condensed Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]	'	'
Convertible preferred stock, par value	$0.00	$0.00	[1]
Convertible preferred stock, shares authorized	0	15,907,322	[1]
Convertible preferred stock, Shares Issued	0	15,701,444	[1]
Convertible preferred stock, shares outstanding	0	15,701,444	[1]
Preferred stock, par value	$0.00	$0.00	[1]
Preferred stock, shares authorized	10,000,000	0	[1]
Preferred stock, shares issued	0	0	[1]
Preferred stock, shares outstanding	0	0	[1]
Common stock, par value	$0.00	$0.00	[1]
Common stock, shares authorized	150,000,000	150,000,000	[1]
Common stock, shares issued	23,368,000	1,761,000	[1]
Common stock, shares outstanding	23,368,000	1,761,000	[1]
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Condensed_Statements_of_Operat

Condensed Statements of Operations and Comprehensive Loss (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'	'	'
Revenue	$9,100	$4,279	$25,162	$10,959
Cost of sales	2,576	1,438	7,256	5,589
Gross profit	6,524	2,841	17,906	5,370
Operating expenses:	'	'	'	'
Selling, general and administrative	9,667	4,700	24,616	12,137
Research and development	2,758	2,077	7,712	6,754
Total operating expenses	12,425	6,777	32,328	18,891
Loss from operations	-5,901	-3,936	-14,422	-13,521
Interest and other income	30	1	96	84
Interest and other expense	-14	-164	-350	-300
Net loss	-5,885	-4,099	-14,676	-13,737
Unrealized gain on short-term investments	6	'	6	'
Comprehensive loss	($5,879)	($4,099)	($14,670)	($13,737)
Net loss per share, basic and diluted	($0.32)	($2.39)	($2)	($10.08)
Weighted average common shares used to compute net loss per share, basic and diluted	18,217	1,718	7,343	1,363

Condensed_Statements_of_Cash_F

Condensed Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Operating activities:	'		'
Net loss	($14,676)		($13,737)
Adjustments to reconcile net loss to cash used in operating activities:	'		'
Depreciation and amortization	434		374
Stock-based compensation expense	1,010		243
Amortization of net investment premium paid	12		'
Change in fair value of convertible preferred stock warrants	198		'
Change in fair value of convertible preferred stock financing option	'		212
Forgiveness of notes receivable from related party	100		100
Changes in operating assets and liabilities:	'		'
Accounts receivable, net	-734		-996
Inventory	-483		-1,002
Prepaid expenses and other current assets	-778		25
Other non-current assets	-38		-2
Accounts payable	592		2
Accrued compensation	1,264		107
Other current liabilities and deferred rent	86		186
Net cash used in operating activities	-13,013		-14,488
Investing activities:	'		'
Purchases of short-term investments	-34,390		'
Purchases of property and equipment	-291		-311
Net cash used in investing activities	-34,681		-311
Financing activities:	'		'
Proceeds from issuance of common stock	190		98
Proceeds from capital lease financing	'		106
Repayments related to equipment loans	-1,365		-476
Repayments related to capital lease financing	-23		-11
Proceeds from initial public offering, net of issuance costs	55,831		'
Proceeds from the exercise of Series A convertible preferred warrants	'		82
Proceeds from issuance of Series D convertible preferred stock, net of issuance costs	'		20,715
Net cash provided by financing activities	54,633		20,514
Net increase in cash and cash equivalents	6,939		5,715
Cash and cash equivalents:	'		'
Beginning of the period	12,294	[1]	2,060
End of the period	$19,233		$7,775
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Organization

Organization	9 Months Ended
	Sep. 30, 2014
Accounting Policies [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-eluting 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 September 30, 2014, the Company had cash, cash equivalents and short-term investments of $53.6 million, and an accumulated deficit of $92.9 million. In July 2014 the Company completed its initial public offering (“IPO”) by issuing 5,750,000 shares of common stock at an offering price of $11.00 per share, for net proceeds of $55.8 million, after deducting underwriting discounts and commissions and offering expenses. 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_Account

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
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”).
	The interim financial data as of September 30, 2014, is unaudited and is not necessarily indicative of the results for a full year. In the opinion of the Company’s management, the interim data includes only normal and recurring adjustments necessary for a fair statement of the Company’s financial results for the three and nine months ended September 30, 2014. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to SEC rules and regulations relating to interim financial statements.
	The accompanying condensed financial statements should be read in conjunction with the Company’s audited financial statements and notes thereto included in the Company’s final prospectus filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended, relating to the Company’s final prospectus (No. 333-196974) (“Final Prospectus”), filed with the SEC on July 24, 2014.
	Certain amounts in the financial statements have been reclassified to conform to the current year presentation.
	1-for-4 Reverse Stock Split
	On July 10, 2014, the Board of Directors and stockholders approved, and on July 11, 2014, 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.
	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, clinical trial accruals, 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.
	Significant Accounting Policies
	There have been no significant changes to the accounting policies during the three and nine months ended September 30, 2014, as compared to the significant accounting policies described in Note 2 of the “Notes to Financial Statements” in the Company’s audited financial statements included in the Final Prospectus other than those listed below.
	Short-term Investments
	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 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.
	Deferred Offering Costs
	Deferred offering costs were capitalized and consisted primarily of legal, accounting and other direct fees and costs related to the IPO. The deferred offering costs were offset against the IPO proceeds upon the closing of the offering in July 2014. There were no deferred offering costs capitalized as of December 31, 2013.
	Recent Accounting Pronouncements
	In June 2014, the Financial Accounting Standard Board (“FASB”) issued Accounting Standards Update (“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 (“ASU 2014-12”). ASU 2014-12 requires that a performance target that affects vesting of share-based payment awards and that could be achieved after the requisite service period be treated as a performance condition. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the periods for which the requisite service has already been rendered. If the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The requisite service period ends when the employee can cease rendering service and still be eligible to vest in the award if the performance target is achieved. ASU 2014-12 is effective for all entities for annual periods and interim periods within those annual periods beginning after December 15, 2015. Early adoption is permitted. An entity may apply the amendments in ASU 2014-12 either (i) prospectively to all awards granted or modified after the effective date or (ii) retrospectively to all awards with performance targets that are outstanding as of the beginning of the earliest annual period presented in the financial statements and to all new or modified awards thereafter. The adoption of ASU 2014-12 is not expected to have a material impact on the Company’s financial condition or results of operations.
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. ASU 2014-09 will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. In doing so, companies will need to use more judgment and make more estimates than under current guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. ASU 2014-09 is effective for all entities for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its financial statements and related disclosures.

Composition_of_Certain_Financi

Composition of Certain Financial Statement Items	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Composition of Certain Financial Statement Items	'
	3	Composition of Certain Financial Statement Items
	Inventory (in thousands):
			September 30,			December 31,
			2014			2013
	Raw materials		$	804		$	472
	Work-in-process			176			241
	Finished goods			1,700			1,484
			$	2,680		$	2,197
	Property and Equipment (in thousands):
			September 30,			December 31,
			2014			2013
	Computer equipment and software		$	566		$	398
	Furniture and office equipment			255			252
	Laboratory equipment			2,424			2,262
	Leasehold improvements			128			124
				3,373			3,036
	Less: accumulated depreciation and amortization			(1,762	)		(1,329	)
			$	1,611		$	1,707
	Depreciation and leasehold improvements and capital lease amortization expenses was $0.1 million and $0.4 million during the three and nine months ended September 30, 2014, respectively, and $0.2 million and $0.4 million during the three and nine months ended September 30, 2013, respectively.
	Prepaid Expenses and Other Current and Non-current Assets (in thousands):
			September 30,			December 31,
			2014			2013
	Prepaid expenses		$	987		$	349
	Interest receivable			201			—
	Note receivable from related party			—			100
	Prepaid expenses and other current assets		$	1,188		$	449
	As of September 30, 2014 and December 31, 2013, other non-current assets consisted of two-thirds of the security deposit on the Company’s operating lease for its headquarters in Menlo Park, California of $0.1 million.
	Other Current Liabilities (in thousands):
			September 30,			December 31,
			2014			2013
	Deferred gross margin		$	230		$	54
	Manufacturing expenses			245			213
	Sales and use tax			119			104
	Deferred rent			83			115
	Facilities expenses			75			104
	Other			80			155
			$	832		$	745
	Interest and Other Income (in thousands):
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014		2013
	Interest income		$	7		$	1		$	8	$	5
	Decrease in fair value of convertible preferred stock warrant			23			—			88		—
	Other			—			—			—		79
			$	30		$	1		$	96	$	84
	Interest and Other Expense (in thousands):
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014		2013
	Interest expense		$	14		$	38		$	64	$	88
	Increase in fair value of convertible preferred stock warrant			—			—			286		—
	Increase in fair value of convertible preferred stock financing option			—			126			—		212
			$	14		$	164		$	350	$	300

Shortterm_Investments

Short-term Investments	9 Months Ended
	Sep. 30, 2014
Cash and Cash Equivalents [Abstract]	'
Short-term Investments	'
	4	Short-term Investments
	The following is a summary of cash, cash equivalents and available-for-sale investments by type of instrument (in thousands):
			September 30,								December 31,
			2014								2013
			Amortized		Gross Unrealized				Estimated		Amortized		Gross Unrealized				Estimated
			Cost		Gains		Losses		Fair Value		Cost		Gains		Losses		Fair Value
	Cash		$	7,731	$	—	$	—	$	7,731	$	1,076	$	—	$	—	$	1,076
	Money market funds			1,985		—		—		1,985		11,218		—		—		11,218
	Corporate debt securities			34,308		2		8		34,302		—		—		—		—
	Commercial paper			9,587		12		—		9,599		—		—		—		—
			$	53,611	$	14	$	8	$	53,617	$	12,294	$	—	$	—	$	12,294
	Reported as:
	Cash and cash equivalents								$	19,233							$	12,294
	Short-term investments									34,384								—
									$	53,617							$	12,294
	Management has the 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 condensed balance sheet. As of September 30, 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 three and nine months ended September 30, 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.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	5	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.
	Short-term Investments
	The following is a summary of cash, cash equivalents and available-for-sale investments by type of instrument measured at fair value on a recurring basis (in thousands):
			September 30,												December 31,
			2014												2013
			Level 1			Level 2			Level 3			Total			Level 1		Level 2		Level 3		Total
	Cash		$	7,731		$	—		$	—		$	7,731		$	1,076	$	—	$	—	$	1,076
	Money market funds			1,985			—			—			1,985			11,218		—		—		11,218
	Corporate debt securities			—			34,302			—			34,302			—		—		—		—
	Commercial paper			—			9,599			—			9,599			—		—		—		—
			$	9,716		$	43,901		$	—		$	53,617		$	12,294	$	—	$	—	$	12,294
	Reported as:
	Cash and cash equivalents											$	19,233								$	12,294
	Short-term investments												34,384									—
												$	53,617								$	12,294
	There were no transfers in and out of Level 1 and Level 2 fair value measurements during the year ended December 31, 2013, and the three and nine months ended September 30, 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 represents 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):
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Beginning of the period		$	429		$	93		$	237		$	93
	Issued			—			10			—			10
	Exercised			—			—			(29	)		—
	Expired			—			—			—			—
	Reclassified to equity (1)			(406	)		—			(406	)		—
	Change in fair value			(23	)		—			198			—
	End of the period		$	—		$	103		$	—		$	103
	-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:
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Expected life (years)			4			2			2			3
	Expected volatility			44	%		50	%		46	%		57	%
	Risk-free interest rate			1.2	%		0.3	%		0.5	%		0.4	%
	Dividend yield			0	%		0	%		0	%		0	%
	Series D Convertible Preferred Stock Financing Option
	The Series D convertible preferred stock 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):
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Beginning of the period		$	—		$	971		$	—		$	—
	Issued			—			—			—			885
	Exercised			—			—			—			—
	Expired			—			—			—			—
	Change in fair value			—			126			—			212
	End of the period		$	—		$	1,097		$	—		$	1,097
	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			September
			2013			2013
	Total consideration per share		$	1.72		$	1.72
	Additional investment per share			1.72			1.72
	Discount rate			20	%		20	%
	Probability of achievement			95	%		95	%
	Years until milestone achieved			0.5			0.7

Notes_Receivable_from_Related_

Notes Receivable from Related Parties	9 Months Ended
	Sep. 30, 2014
Receivables [Abstract]	'
Notes Receivable from Related Parties	'
	6	Notes Receivable from Related Parties
	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. The promissory notes were issued in May 2013 for $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 remained 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) 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 entire principal amount and all accrued and unpaid interest of the loan was forgiven in full in June 2014. The full recourse promissory notes were secured by a pledge of the exercised shares.
	In January 2007, the Company loaned amounts to its Chief Operation Officer, Mr. Kaufman, a related party in connection with the commencement of Mr. Kaufman’s employment with the Company. The loan was evidenced by a promissory note for $0.3 million. The note bore interest at the applicable federal rate and interest was determined in accordance with Section 7872 of the Internal Revenue Code and had been reflected as income to the employee. Pursuant to the terms of the promissory note, provided Mr. Kaufman remained a continuous, full-time employee of the Company, repayment of the notes was to begin after the third year of employment when 50% of Mr. Kaufman’s annual bonus would have been applied to the loan balance until the loan was paid in full. The note was to mature and become immediately due and payable within 30 days following the date on which Mr. Kaufman ceased, voluntarily or involuntarily, to be employed by the Company. No payment was received in the year ended December 31, 2011, since the Company did not pay an annual bonus in that year. In February 2011, the Company agreed to forgive Mr. Kaufman’s loan over three years, provided Mr. Kaufman remained employed by the Company, with $0.1 million forgiven in January 2012, $0.1 million in January 2013 and $0.1 million in January 2014. The note was secured by any stock and options Mr. Kaufman held in the Company. The note receivable balance outstanding at December 31, 2013 was $0.1 million. Mr. Kaufman’s note was fully forgiven in January 2014.

Loan_and_Security_Agreement

Loan and Security Agreement	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Loan and Security Agreement	'
	7	Loan and Security Agreement
	In August 2013, the Company entered into a loan and security agreement (“Loan Agreement”) with Silicon Valley Bank (“SVB”) for a total commitment of $12.0 million. The commitment consisted of an $8.0 million growth capital facility and a $4.0 million revolving accounts receivable line of credit. In August 2014, the Company cancelled the Loan Agreement and had not received any advances under the Loan Agreement.
	The $8.0 million growth capital facility consisted of two $4.0 million tranches. The first $4.0 million tranche was available immediately upon execution of the Loan Agreement and was available until October 31, 2014. The second $4.0 million tranche was contingent upon the Company achieving a trailing three-month revenue of at least $7.0 million. The Company achieved that condition as of January 31, 2014, and therefore the second tranche was available until March 31, 2015. Payments under both tranches would have been interest-only until March 31, 2015, at which time the outstanding balance would have converted to a 30-month fully amortizing loan. The interest rate would have been fixed at the time of advance and would have been the greater of 3.65% or the three-year U.S. Treasury note plus 3%. At the end of the amortization period, the Company would have made a final payment of 3.9% of the advanced amounts. There was a prepayment penalty of 2% of the prepaid principal during the first year, 1% during the second year and no prepayment penalty during the third year.
	In addition, the Company issued a warrant to SVB to purchase up to 20,313 shares of the Company’s Series D convertible preferred stock for an aggregate exercise price of 0.5% of the total growth capital facility commitment, or $40,000. Following any draw-downs under the growth capital facility, the warrant would have become exercisable for additional shares of Series D convertible preferred stock equal to 1.25% of the advanced amounts under tranche one and two divided by $6.89. The initial value of the warrants issued was $10,000 and has been recognized as convertible preferred stock warrant liability and interest expense. In connection with the IPO, the warrants to purchase convertible preferred stock were converted to warrants to purchase common stock and any additional warrants that would have become exercisable under the terms of the Loan Agreement would have been exercisable for common stock. As of September 30, 2014, this warrant was exercisable for 5,803 shares of the Company’s common stock at an exercise price of $6.89 per share.
	The $4.0 million revolving accounts receivable line of credit would have expired in August 2016. Advances would have been made for up to 80% of eligible accounts receivable. An annual loan fee of 0.75% would have been paid at the beginning of each of the three years. The interest would have been the greater of 4.25% or SVB Prime Rate plus 0.25%.

Equipment_Loans

Equipment Loans	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Equipment Loans	'
	8	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 to be made in monthly installments over a 36-month period with an annual interest rate of 5.1%. A total of $6,000 and $36,000 was recorded as interest expense during the three and nine months ended September 30, 2014, respectively, and $21,000 and $67,000 during the three and nine months ended September 30, 2013, respectively. The amount outstanding under this loan at December 31, 2013 was $1.4 million. 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 will be made in monthly installments over a 38-month period with an interest rate of 14.88%. The amounts outstanding under this loan at September 30, 2014 and December 31, 2013, were $65,000 and $87,000, respectively.
	At September 30, 2014 and December 31, 2013, future minimum payments under these equipment loans are as follows (in thousands):
	Year Ending December 31,		September 30,			December 31,
			2014			2013
	2014 (remaining)		$	10		$	761
	2015			42			761
	2016			21			21
	Thereafter			—			—
	Total minimum payments			73			1,543
	Less: amount representing interest			(8	)		(91	)
	Present value of future payments			65			1,452
	Less: current portion			(35	)		(696	)
	Non-current portion		$	30		$	756

Convertible_Preferred_Stock_Wa

Convertible Preferred Stock Warrant Liability	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Convertible Preferred Stock Warrant Liability	'
	9	Convertible Preferred Stock Warrant Liability
	As of September 30, 2014 and December 31, 2013, the following warrants to purchase shares of convertible preferred stock were outstanding and exercisable (in thousands, except share and per share data):
	Dates			In Connection With	Series			Warrants Outstanding at				Initial		Fair Value at
	Issuance		Expiration			Exercise		September 30,		December 31,		Value		September 30,		December 31,
						Price		2014		2013				2014 (1)		2013
	Mar-07		Mar-14	Equipment loan	A	$	3.68		—		4,076	$	4	$	—	$	17
	Nov-07		Nov-17	Venture loan	A	$	3.68		47,554		47,554		63		—		200
	Aug-13		Aug-23	Loan Agreement	D	$	6.89		5,803		5,803		10		—		20
									53,357		57,433			$	—	$	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 of $0.4 million to additional paid-in capital.
	During the nine months ended September 30, 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 the remaining 1,645 shares were withheld for the exercise price. During the nine months ended September 30, 2013, warrants to purchase 22,418 shares of Series A convertible preferred stock were exercised at a price of $3.68 per share.
	In connection with the execution of the Loan Agreement in August 2013, warrants were issued to purchase the Company’s Series D convertible preferred stock. The warrants are initially exercisable for 5,803 shares of Series D convertible preferred stock at an exercise price of $6.89 per share. Alternatively, the bank has the option to exercise the warrants to purchase shares of the class of equity sold to investors in a future round of equity financing with proceeds of at least $5.0 million. The exercise price would be the price paid by the lead investor in the new financing and the number of shares exercisable would be based on an aggregate exercise price of $40,000, representing 0.5% of the total growth capital facility. This represented a warrant for 5,803 shares at an exercise price of $6.89 per share as of September 30, 2014 and December 31, 2013. The warrants expire in August 2023 or upon the occurrence of an acquisition of the Company in exchange for cash or marketable securities.
	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

Convertible Preferred Stock	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Convertible Preferred Stock	'
	10	Convertible Preferred Stock
	A summary of the Company’s convertible preferred stock is as follows:
			September 30, 2014 (1)						December 31, 2013
	Series		Shares		Shares		Carrying		Shares		Shares		Carrying
			Authorized		Issued and		Value		Authorized		Issued and		Value
					Outstanding		(in thousands)				Outstanding		(in thousands)
	A			—		—	$	—		2,796,259		2,744,619	$	9,987
	B			—		—		—		3,249,662		3,249,657		19,894
	C			—		—		—		5,311,401		5,311,395		30,521
	D			—		—		—		4,550,000		4,395,773		30,358
				—		—	$	—		15,907,322		15,701,444	$	90,760
	-1	In connection with the Company’s IPO in July 2014, the convertible preferred stock was converted into 15,703,875 shares 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.
	Series D Convertible Preferred Stock
	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.

Stockholders_Equity

Stockholder's Equity	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Stockholder's Equity	'
	11	Stockholder’s 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.
	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 three and nine months ended September 30, 2014 and no options issued with 100% of the shares vested as of the date of grant during the three and nine months ended September 30, 2013. Options outstanding under the 2013 Plan will expire upon forfeiture. As of September 30, 2014, 0.6 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 (options in thousands):
			Nine Months Ended
			September 30,
			2014
			Options			Price
	Outstanding, beginning of period			1,928		$	1.08
	Granted			622			11.44
	Exercised			(153	)		1.43
	Forfeited			(89	)		1.47
	Expired			—			—
	Outstanding, end of period			2,308			3.82
	Vested and expected to vest			2,302			3.57
	Exercisable			1,514			2.41
	As of September 30, 2014, the aggregate pre-tax intrinsic value of options outstanding and exercisable was $19.8 million and options outstanding were $27.1 million. The aggregate pre-tax intrinsic value of options exercised was $1.4 million and $0.3 million during the nine months ended September 30, 2014 and 2013, respectively. The aggregate pre-tax intrinsic value was calculated as the difference between the exercise prices of the underlying options and the fair market value of the common stock on the date of exercise. The total cash received upon the exercise of options was $0.2 million and $0.6 million during the nine months ended September 30, 2014 and 2013, respectively.
	Early Exercise of Stock Options
	Stock options granted under the Plan may provide option holders the right to elect to exercise unvested options in exchange for restricted common stock. During the year ended December 31, 2013, employees exercised options with 69,037 unvested shares. As of September 30, 2014 and December 31, 2013, 36,898 and 53,796 shares, respectively, remained subject to a repurchase right held by the Company at the original issuance price in the event the optionees’ service is voluntarily or involuntarily terminated. As of September 30, 2014 and December 31, 2013, the related liability was $33,000 and $31,000, 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. Additionally, the number of shares of common stock reserved for issuance under the 2014 ESPP will increase automatically each year, beginning on January 1, 2015, and continuing through and including January 1, 2024, by the lesser of (1) 1% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year; or (2) such lesser number as determined by the Company’s board of directors. As of September 30, 2014, the Company has not implemented the 2014 ESPP.

StockBased_Compensation_Expens

Stock-Based Compensation Expense	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation Expense	'
	12	Stock-Based Compensation Expense
	Total stock-based compensation expense recognized, before taxes, during the three and nine months ended September 30, 2014 and 2013, are as follows (in thousands):
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Cost of sales		$	14		$	6		$	36		$	14
	Selling, general and administrative			390			84			870			169
	Research and development			37			23			104			60
			$	441		$	113		$	1,010		$	243
	The amount of unearned stock-based compensation currently estimated to be expensed from now through the year 2018 related to unvested employee stock-based payment awards as of September 30, 2014 is $3.5 million. The weighted average period over which the unearned stock-based compensation is expected to be recognized as of September 30, 2014, is 3.0 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 recognized in the financial statements is based on awards ultimately expected to vest, it has been reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from estimates. Forfeitures are estimated based on estimated future employee turnover and historical experience.
	The fair value of the options granted to employees or directors during the three and nine months ended September 30, 2014 and 2013, was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table:
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Expected life (years)			6			6			6			6
	Expected volatility			56	%		66	%		58	%		67	%
	Risk-free interest rate			1.8	%		2.2	%		1.9	%		1.6	%
	Dividend yield			0	%		0	%		0	%		0	%
	Weighted average fair value		$	7.15		$	0.72		$	5.95		$	0.72
	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 $13,000 and $0.2 million was recognized during three and nine months ended September 30, 2014, respectively, and $21,000 and $29,000 was recognized during the three and nine months ended September 30, 2013, respectively.
	The entire principal amount and all accrued and unpaid interest of the loan was forgiven in full in June 2014. 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 will be amortized over the remaining vesting period.
	Performance-Based Options
	Options issued in February 2011, included grants to certain employees totaling 289,253 shares that contained vesting conditions contingent on the achievement of certain milestones. Assuming continued service by the employee, the vesting would begin on the date both milestones were achieved and vest monthly thereafter over the following four years. The Company determined that it was probable that both milestones would be achieved and therefore began recording stock-based compensation expense related to these options in the year ended December 31, 2011. The milestones were achieved by the year ended December 31, 2013, and therefore began vesting accordingly. Stock-based compensation expense totaling $4,000 and $13,000 was recorded during the three and nine months ended September 30, 2014, respectively, and $7,000 and $22,000 during the three and nine months ended September 30, 2013, respectively.
	Options issued in April 2013, included grants to certain employees totaling 363,000 shares that contained vesting conditions contingent on the achievement of certain milestones. Assuming continued service by the employee, the vesting would begin on the date both milestones were achieved and vest monthly over the following four years. The Company determined it was probable that both milestones would be achieved and therefore began recording stock-based compensation expense related to these options in the year ended December 31, 2013. The milestones were achieved by the year ended December 31, 2013, and therefore began vesting accordingly. Stock-based compensation expense totaling $19,000 and $0.1 million were recorded during the three and nine months ended September 30, 2014, respectively, and $29,000 and $51,000 during the three and nine months ended September 30, 2013, respectively.
	Options Issued to Consultants
	In September 2013, non-statutory options were issued to non-employees to purchase 5,000 shares of common stock for current and future services at weighted-average exercise prices of $1.20 per share, respectively. There were no options issued to non-employees during the three and nine months ended September 30, 2014. The options were valued using the Black-Scholes model based on the following weighted average assumptions:
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Expected life (years)			9			9			9			9
	Expected volatility			56	%		66	%		61	%		66	%
	Risk-free interest rate			2.5	%		2.8	%		2.6	%		2.4	%
	Dividend yield			0	%		0	%		0	%		0	%
	The fair value of these options is expensed over the vesting period, which ranges from five months to three years. Stock-based compensation expense was $51,000 and $0.1 million during the three and nine months ended September 30, 2014, respectively, and $2,000 and $5,000 during the three and nine months ended September 30, 2013, respectively, related to consultants was charged to expense in the statements of operations.

Net_Loss_per_Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Net Loss per Share	'
	13	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 they 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):
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Net loss		$	(5,885	)	$	(4,099	)	$	(14,676	)	$	(13,737	)
	Weighted average common stock outstanding			18,217			1,718			7,343			1,363
	Net loss per share, basic and diluted		$	(0.32	)	$	(2.39	)	$	(2.00	)	$	(10.08	)
	The following potentially dilutive securities outstanding have been excluded from the computations of diluted weighted average shares outstanding because such securities have an antidilutive impact due to losses reported, in common stock equivalent shares (in thousands):
			September 30,
			2014			2013
	Convertible preferred stock outstanding (1)			—			14,332
	Convertible preferred stock warrants (1)			—			57
	Common stock warrants (1)			53			—
	Common stock options			2,308			1,876
				2,361			16,265
	-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.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	14	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 September 30, 2014 and December 31, 2013, the Company has one leased facility under an operating lease agreement. Rental payments on operating leases are charged to expense on a straight-line basis over the period of the lease. The Company entered into this 36-month lease in March 2012, effective June 1, 2012, for a facility with larger production and office space. 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.
	Future minimum annual operating lease payments are as follows (in thousands):
			September 30,		December 31,
	Year Ending December 31,		2014		2013
	2014 (remaining)		$	235	$	928
	2015			390		390
	Thereafter			—		—
				625		1,318
	Rent expense was $0.3 million and $1.0 million during the three and nine months ended September 30, 2014, respectively, and $0.3 million and $1.1 million during the three and nine months ended September 30, 2013, respectively.
	Purchase Commitments
	The Company had commitments to suppliers for purchases totaling $0.7 million and $0.5 million as of September 30, 2014 and December 31, 2013, respectively.

Related_Parties

Related Parties	9 Months Ended
	Sep. 30, 2014
Related Party Transactions [Abstract]	'
Related Parties	'
	15	Related Parties
	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. The promissory notes were issued in May 2013 for $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 entire principal amount and all accrued and unpaid interest of the loan was forgiven in full in June 2014.The full recourse promissory notes were secured by a pledge of the exercised shares.
	In January 2007, the Company loaned amounts to its Chief Operation Officer, Mr. Kaufman, a related party in connection with the commencement of Mr. Kaufman’s employment with the Company. The loan was evidenced by a promissory note for $0.3 million. The note bore interest at the applicable federal rate and interest was determined in accordance with Section 7872 of the Internal Revenue Code and had been reflected as income to the employee. Pursuant to the terms of the promissory note, provided Mr. Kaufman remained a continuous, full-time employee of the Company, repayment of the notes was to begin after the third year of employment when 50% of Mr. Kaufman’s annual bonus would have been applied to the loan balance until the loan was paid in full. The note was to mature and become immediately due and payable within 30 days following the date on which Mr. Kaufman ceased, voluntarily or involuntarily, to be employed by the Company. No payment was received in the year ended December 31, 2011, since the Company did not pay an annual bonus in that year. In February 2011, the Company agreed to forgive Mr. Kaufman’s loan over three years, provided Mr. Kaufman remained employed by the Company, with $0.1 million forgiven in January 2012, $0.1 million in January 2013 and $0.1 million in January 2014. The notes are secured by any stock and options Mr. Kaufman holds in the Company. The note receivable balance outstanding at December 31, 2013 was $0.1 million. Mr. Kaufman’s note was fully forgiven in January 2014.
	In March 2009, the Company purchased three sinus irrigation tool patents from Medilyfe Inc., a Canadian corporation. A member of the Company’s Medical Advisory Board holds an executive-level position with Medilyfe Inc. The agreement called for a $40,000 payment upon execution of the agreement and an additional $35,000 upon the first anniversary of the agreement’s effective date in addition to the issuance of a warrant to purchase 47,350 shares of the Company’s common stock at $1.00 per share.
	The warrant vested fully upon grant and will expire April 7, 2019. The value of the warrant was $30,000 determined using the Black-Scholes model. The cost of the patents is included in research and development expense, since substantial research and development efforts were required at the time of the payment of these amounts and there was no alternative future use of the technology rights. A $35,000 cash payment was made in 2012, since one additional patent claim was allowed by the U.S. Patent Office. The Company recorded $35,000 in research and development expense related to this agreement for the year ended December 31, 2012. An additional $80,000 cash payment will be due upon the first achievement of net sales of products incorporating this technology exceeding $1.0 million in a given calendar year. Such additional payment was not owed as of September 30, 2014 and December 31, 2013, since this technology is unrelated to the Company’s current activities.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
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”).
	The interim financial data as of September 30, 2014, is unaudited and is not necessarily indicative of the results for a full year. In the opinion of the Company’s management, the interim data includes only normal and recurring adjustments necessary for a fair statement of the Company’s financial results for the three and nine months ended September 30, 2014. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to SEC rules and regulations relating to interim financial statements.
	The accompanying condensed financial statements should be read in conjunction with the Company’s audited financial statements and notes thereto included in the Company’s final prospectus filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended, relating to the Company’s final prospectus (No. 333-196974) (“Final Prospectus”), filed with the SEC on July 24, 2014.
Financial Statements Reclassification	'
	Certain amounts in the financial statements have been reclassified to conform to the current year presentation.
	1-for-4 Reverse Stock Split
	On July 10, 2014, the Board of Directors and stockholders approved, and on July 11, 2014, 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.
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, clinical trial accruals, 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.
Significant Accounting Policies	'
	Significant Accounting Policies
	There have been no significant changes to the accounting policies during the three and nine months ended September 30, 2014, as compared to the significant accounting policies described in Note 2 of the “Notes to Financial Statements” in the Company’s audited financial statements included in the Final Prospectus other than those listed below.
Short-term Investments	'
	Short-term Investments
	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 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.
Deferred Offering Costs	'
	Deferred Offering Costs
	Deferred offering costs were capitalized and consisted primarily of legal, accounting and other direct fees and costs related to the IPO. The deferred offering costs were offset against the IPO proceeds upon the closing of the offering in July 2014. There were no deferred offering costs capitalized as of December 31, 2013.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In June 2014, the Financial Accounting Standard Board (“FASB”) issued Accounting Standards Update (“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 (“ASU 2014-12”). ASU 2014-12 requires that a performance target that affects vesting of share-based payment awards and that could be achieved after the requisite service period be treated as a performance condition. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the periods for which the requisite service has already been rendered. If the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The requisite service period ends when the employee can cease rendering service and still be eligible to vest in the award if the performance target is achieved. ASU 2014-12 is effective for all entities for annual periods and interim periods within those annual periods beginning after December 15, 2015. Early adoption is permitted. An entity may apply the amendments in ASU 2014-12 either (i) prospectively to all awards granted or modified after the effective date or (ii) retrospectively to all awards with performance targets that are outstanding as of the beginning of the earliest annual period presented in the financial statements and to all new or modified awards thereafter. The adoption of ASU 2014-12 is not expected to have a material impact on the Company’s financial condition or results of operations.
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. ASU 2014-09 will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. In doing so, companies will need to use more judgment and make more estimates than under current guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. ASU 2014-09 is effective for all entities for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its financial statements and related disclosures.

Composition_of_Certain_Financi1

Composition of Certain Financial Statement Items (Tables)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Components of Inventory	'
	Inventory (in thousands):
		September 30,			December 31,
		2014			2013
	Raw materials	$	804		$	472
	Work-in-process		176			241
	Finished goods		1,700			1,484
		$	2,680		$	2,197
Property and Equipment	'
	Property and Equipment (in thousands):
		September 30,			December 31,
		2014			2013
	Computer equipment and software	$	566		$	398
	Furniture and office equipment		255			252
	Laboratory equipment		2,424			2,262
	Leasehold improvements		128			124
			3,373			3,036
	Less: accumulated depreciation and amortization		(1,762	)		(1,329	)
		$	1,611		$	1,707
Prepaid Expenses and Other Current and Non-current Assets	'
	Prepaid Expenses and Other Current and Non-current Assets (in thousands):
		September 30,			December 31,
		2014			2013
	Prepaid expenses	$	987		$	349
	Interest receivable		201			—
	Note receivable from related party		—			100
	Prepaid expenses and other current assets	$	1,188		$	449
Other Current Liabilities	'
	Other Current Liabilities (in thousands):
		September 30,			December 31,
		2014			2013
	Deferred gross margin	$	230		$	54
	Manufacturing expenses		245			213
	Sales and use tax		119			104
	Deferred rent		83			115
	Facilities expenses		75			104
	Other		80			155
		$	832		$	745
Interest and Other Income	'
	Interest and Other Income (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014		2013
	Interest income	$	7		$	1		$	8	$	5
	Decrease in fair value of convertible preferred stock warrant		23			—			88		—
	Other		—			—			—		79
		$	30		$	1		$	96	$	84
Interest and Other Expense	'
	Interest and Other Expense (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014		2013
	Interest expense	$	14		$	38		$	64	$	88
	Increase in fair value of convertible preferred stock warrant		—			—			286		—
	Increase in fair value of convertible preferred stock financing option		—			126			—		212
		$	14		$	164		$	350	$	300

Shortterm_Investments_Tables

Short-term Investments (Tables)	9 Months Ended
	Sep. 30, 2014
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 available-for-sale investments by type of instrument (in thousands):
		September 30,								December 31,
		2014								2013
		Amortized		Gross Unrealized				Estimated		Amortized		Gross Unrealized				Estimated
		Cost		Gains		Losses		Fair Value		Cost		Gains		Losses		Fair Value
	Cash	$	7,731	$	—	$	—	$	7,731	$	1,076	$	—	$	—	$	1,076
	Money market funds		1,985		—		—		1,985		11,218		—		—		11,218
	Corporate debt securities		34,308		2		8		34,302		—		—		—		—
	Commercial paper		9,587		12		—		9,599		—		—		—		—
		$	53,611	$	14	$	8	$	53,617	$	12,294	$	—	$	—	$	12,294
	Reported as:
	Cash and cash equivalents							$	19,233							$	12,294
	Short-term investments								34,384								—
								$	53,617							$	12,294

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2014
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 available-for-sale investments by type of instrument measured at fair value on a recurring basis (in thousands):
			September 30,												December 31,
			2014												2013
			Level 1			Level 2			Level 3			Total			Level 1		Level 2		Level 3		Total
	Cash		$	7,731		$	—		$	—		$	7,731		$	1,076	$	—	$	—	$	1,076
	Money market funds			1,985			—			—			1,985			11,218		—		—		11,218
	Corporate debt securities			—			34,302			—			34,302			—		—		—		—
	Commercial paper			—			9,599			—			9,599			—		—		—		—
			$	9,716		$	43,901		$	—		$	53,617		$	12,294	$	—	$	—	$	12,294
	Reported as:
	Cash and cash equivalents											$	19,233								$	12,294
	Short-term investments												34,384									—
												$	53,617								$	12,294
Convertible Preferred Stock Warrant Liability [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 represents 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):
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Beginning of the period		$	429		$	93		$	237		$	93
	Issued			—			10			—			10
	Exercised			—			—			(29	)		—
	Expired			—			—			—			—
	Reclassified to equity (1)			(406	)		—			(406	)		—
	Change in fair value			(23	)		—			198			—
	End of the period		$	—		$	103		$	—		$	103
	-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:
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Expected life (years)			4			2			2			3
	Expected volatility			44	%		50	%		46	%		57	%
	Risk-free interest rate			1.2	%		0.3	%		0.5	%		0.4	%
	Dividend yield			0	%		0	%		0	%		0	%
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):
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Beginning of the period		$	—		$	971		$	—		$	—
	Issued			—			—			—			885
	Exercised			—			—			—			—
	Expired			—			—			—			—
	Change in fair value			—			126			—			212
	End of the period		$	—		$	1,097		$	—		$	1,097
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			September
			2013			2013
	Total consideration per share		$	1.72		$	1.72
	Additional investment per share			1.72			1.72
	Discount rate			20	%		20	%
	Probability of achievement			95	%		95	%
	Years until milestone achieved			0.5			0.7

Equipment_Loans_Tables

Equipment Loans (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Future Minimum Payments under Equipment Loans	'
	At September 30, 2014 and December 31, 2013, future minimum payments under these equipment loans are as follows (in thousands):
	Year Ending December 31,	September 30,			December 31,
		2014			2013
	2014 (remaining)	$	10		$	761
	2015		42			761
	2016		21			21
	Thereafter		—			—
	Total minimum payments		73			1,543
	Less: amount representing interest		(8	)		(91	)
	Present value of future payments		65			1,452
	Less: current portion		(35	)		(696	)
	Non-current portion	$	30		$	756

Convertible_Preferred_Stock_Wa1

Convertible Preferred Stock Warrant Liability (Tables)	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Schedule of Warrants to Purchase Shares of Convertible Preferred Stock Outstanding and Exercisable	'
	As of September 30, 2014 and December 31, 2013, the following warrants to purchase shares of convertible preferred stock were outstanding and exercisable (in thousands, except share and per share data):
	Dates			In Connection With	Series			Warrants Outstanding at				Initial		Fair Value at
	Issuance		Expiration			Exercise		September 30,		December 31,		Value		September 30,		December 31,
						Price		2014		2013				2014 (1)		2013
	Mar-07		Mar-14	Equipment loan	A	$	3.68		—		4,076	$	4	$	—	$	17
	Nov-07		Nov-17	Venture loan	A	$	3.68		47,554		47,554		63		—		200
	Aug-13		Aug-23	Loan Agreement	D	$	6.89		5,803		5,803		10		—		20
									53,357		57,433			$	—	$	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 of $0.4 million to additional paid-in capital.

Convertible_Preferred_Stock_Ta

Convertible Preferred Stock (Tables)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Summary of Convertible Preferred Stock	'
	A summary of the Company’s convertible preferred stock is as follows:
			September 30, 2014 (1)						December 31, 2013
	Series		Shares		Shares		Carrying		Shares		Shares		Carrying
			Authorized		Issued and		Value		Authorized		Issued and		Value
					Outstanding		(in thousands)				Outstanding		(in thousands)
	A			—		—	$	—		2,796,259		2,744,619	$	9,987
	B			—		—		—		3,249,662		3,249,657		19,894
	C			—		—		—		5,311,401		5,311,395		30,521
	D			—		—		—		4,550,000		4,395,773		30,358
				—		—	$	—		15,907,322		15,701,444	$	90,760
	-1	In connection with the Company’s IPO in July 2014, the convertible preferred stock was converted into 15,703,875 shares 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.

Stockholders_Equity_Tables

Stockholder's Equity (Tables)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Summary of Stock Option Activity	'
	A summary of the Company’s stock option activity and related information is as follows (options in thousands):
		Nine Months Ended
		September 30,
		2014
		Options			Price
	Outstanding, beginning of period		1,928		$	1.08
	Granted		622			11.44
	Exercised		(153	)		1.43
	Forfeited		(89	)		1.47
	Expired		—			—
	Outstanding, end of period		2,308			3.82
	Vested and expected to vest		2,302			3.57
	Exercisable		1,514			2.41

StockBased_Compensation_Expens1

Stock-Based Compensation Expense (Tables)	9 Months Ended
	Sep. 30, 2014
Summary of Stock Based Compensation Recognized Before Taxes	'
	Total stock-based compensation expense recognized, before taxes, during the three and nine months ended September 30, 2014 and 2013, are as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Cost of sales	$	14		$	6		$	36		$	14
	Selling, general and administrative		390			84			870			169
	Research and development		37			23			104			60
		$	441		$	113		$	1,010		$	243
Summary of Weighted Average Assumptions Used to Estimate Options Using Black-Scholes Model	'
	The fair value of the options granted to employees or directors during the three and nine months ended September 30, 2014 and 2013, was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Expected life (years)		6			6			6			6
	Expected volatility		56	%		66	%		58	%		67	%
	Risk-free interest rate		1.8	%		2.2	%		1.9	%		1.6	%
	Dividend yield		0	%		0	%		0	%		0	%
	Weighted average fair value	$	7.15		$	0.72		$	5.95		$	0.72
Consultants [Member]	'
Summary of Weighted Average Assumptions Used to Estimate Options Using Black-Scholes Model	'
	The options were valued using the Black-Scholes model based on the following weighted average assumptions:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Expected life (years)		9			9			9			9
	Expected volatility		56	%		66	%		61	%		66	%
	Risk-free interest rate		2.5	%		2.8	%		2.6	%		2.4	%
	Dividend yield		0	%		0	%		0	%		0	%

Net_Loss_per_Share_Tables

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Schedule of Net Loss Per Share	'
	Net loss per share was determined as follows (in thousands, except per share amounts):
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
	Net loss		$	(5,885	)	$	(4,099	)	$	(14,676	)	$	(13,737	)
	Weighted average common stock outstanding			18,217			1,718			7,343			1,363
	Net loss per share, basic and diluted		$	(0.32	)	$	(2.39	)	$	(2.00	)	$	(10.08	)
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 diluted weighted average shares outstanding because such securities have an antidilutive impact due to losses reported, in common stock equivalent shares (in thousands):
			September 30,
			2014			2013
	Convertible preferred stock outstanding (1)			—			14,332
	Convertible preferred stock warrants (1)			—			57
	Common stock warrants (1)			53			—
	Common stock options			2,308			1,876
				2,361			16,265
	-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.

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Summary of Future Minimum Annual Operating Lease Payments	'
	Future minimum annual operating lease payments are as follows (in thousands):
		September 30,		December 31,
	Year Ending December 31,	2014		2013
	2014 (remaining)	$	235	$	928
	2015		390		390
	Thereafter		—		—
			625		1,318

Organization_Additional_Inform

Organization - Additional Information (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'	'
Cash, cash equivalents and short-term investments	$53,600,000	'
Accumulated deficit	$92,935,000	$78,259,000	[1]
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Organization_Additional_Inform1

Organization - Additional Information 1 (Detail) (Common Stock [Member], Initial Public Offering [Member], USD $)	0 Months Ended
In Millions, except Share data, unless otherwise specified	Jul. 31, 2014	Jul. 24, 2014	Jul. 31, 2014	Jul. 24, 2014
Common Stock [Member] | Initial Public Offering [Member]	'	'	'	'
Subsidiary, Sale of Stock [Line Items]	'	'	'	'
Common stock issued during period, shares	5,750,000	5,750,000	'	'
Common stock issued during period, price per share	'	'	$11	$11
Net proceeds from initial public offering	$55.80	$55.80	'	'

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information 1 (Detail) (USD $)	0 Months Ended	1 Months Ended	9 Months Ended		1 Months Ended	9 Months Ended	0 Months Ended				0 Months Ended
In Millions, except Share data, unless otherwise specified	Jul. 11, 2014	Jul. 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Jul. 31, 2014	Sep. 30, 2014	Jul. 31, 2014	Jul. 24, 2014	Jul. 31, 2014	Jul. 24, 2014	Jul. 31, 2014
					Common Stock [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]
							Initial Public Offering [Member]	Initial Public Offering [Member]	Initial Public Offering [Member]	Initial Public Offering [Member]	Over-Allotment Option [Member]
Subsidiary, Sale of Stock [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Reverse stock split	'	'	'	'	'	'1-for-4 reverse stock split	'	'	'	'	'
Reverse stock split, ratio	0.25	'	'	'	'	'	'	'	'	'	'
Common stock issued during period, shares	'	'	'	'	'	'	5,750,000	5,750,000	'	'	750,000
Common stock issued during period, price per share	'	'	'	'	'	'	'	'	$11	$11	'
Net proceeds from initial public offering	'	'	'	'	'	'	$55.80	$55.80	'	'	'
Underwriting discounts and commissions	'	'	'	'	'	'	4.5	'	'	'	'
Initial public offering, expenses	'	'	'	'	'	'	3	'	'	'	'
Convertible preferred stock converted into shares of common stock	'	'	'	'	15,703,875	'	15,703,875	'	'	'	'
Warrants exercisable for common stock shares	'	'	53,357	57,433	'	'	'	'	53,357	'	'
Warrant liability to additional paid-in capital	'	$0.40	$0.40	'	'	'	$0.40	'	'	'	'

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	Dec. 31, 2013
Accounting Policies [Abstract]	'
Deferred offering costs capitalized	$0

Composition_of_Certain_Financi2

Composition of Certain Financial Statement Items - Components of Inventory (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Raw materials	$804	$472
Work-in-process	176	241
Finished goods	1,700	1,484
Inventory, net	$2,680	$2,197	[1]
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Composition_of_Certain_Financi3

Composition of Certain Financial Statement Items - Property and Equipment (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Plant and equipment, gross	$3,373	$3,036
Less: accumulated depreciation and amortization	-1,762	-1,329
Plant and equipment, net	1,611	1,707	[1]
Computer Equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Plant and equipment, gross	566	398
Furniture and Fixtures [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Plant and equipment, gross	255	252
Equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Plant and equipment, gross	2,424	2,262
Leasehold Improvements [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Plant and equipment, gross	$128	$124
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Composition_of_Certain_Financi4

Composition of Certain Financial Statement Items - Additional information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Statement of Financial Position [Abstract]	'	'	'	'	'
Depreciation and leasehold improvements and capital lease amortization expenses	$100,000	$200,000	$434,000	$374,000	'
Operating lease	$100,000	'	$100,000	'	$100,000

Composition_of_Certain_Financi5

Composition of Certain Financial Statement Items - Prepaid Expenses and Other Current and Non- current Assets (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'	'
Prepaid expenses	$987	$349
Interest receivable	201	'
Note receivable from related party	'	100
Prepaid expenses and other current assets	$1,188	$449	[1]
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Composition_of_Certain_Financi6

Composition of Certain Financial Statement Items - Other Current Liabilities (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other Liabilities Disclosure [Abstract]	'	'
Deferred gross margin	$230	$54
Manufacturing expenses	245	213
Sales and use tax	119	104
Deferred rent	83	115
Facilities expenses	75	104
Other	80	155
Other current liabilities	$832	$745	[1]
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Composition_of_Certain_Financi7

Composition of Certain Financial Statement Items - Interest and Other Income (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'	'	'
Interest income	$7	$1	$8	$5
Decrease in fair value of convertible preferred stock warrant	-23	'	198	'
Other	'	'	'	79
Interest and other Income	$30	$1	$96	$84

Composition_of_Certain_Financi8

Composition of Certain Financial Statement Items - Interest and Other Expense (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'	'	'
Interest expense	$14	$38	$64	$88
Increase in fair value of convertible preferred stock warrant	'	'	286	'
Change in fair value of convertible preferred stock financing option	'	126	'	212
Interest and other expense	$14	$164	$350	$300

Shortterm_Investments_Summary_

Short-term Investments - Summary of Cash, Cash Equivalents and Available-for-Sale Investments by Type of Instrument (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Net Investment Income [Line Items]	'	'
Cash, cash equivalents and available-for-sale investments, Amortized Cost	$53,611	$12,294
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Gains	14	'
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Losses	8	'
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	53,617	12,294
Cash and Cash Equivalents [Member]	'	'
Net Investment Income [Line Items]	'	'
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	19,233	12,294
Short-term Investments [Member]	'	'
Net Investment Income [Line Items]	'	'
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	34,384	'
Cash [Member]	'	'
Net Investment Income [Line Items]	'	'
Cash, cash equivalents and available-for-sale investments, Amortized Cost	7,731	1,076
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	7,731	1,076
Money Market Funds [Member]	'	'
Net Investment Income [Line Items]	'	'
Cash, cash equivalents and available-for-sale investments, Amortized Cost	1,985	11,218
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	1,985	11,218
Corporate Debt Securities [Member]	'	'
Net Investment Income [Line Items]	'	'
Cash, cash equivalents and available-for-sale investments, Amortized Cost	34,308	'
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Gains	2	'
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Losses	8	'
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	34,302	'
Commercial Paper [Member]	'	'
Net Investment Income [Line Items]	'	'
Cash, cash equivalents and available-for-sale investments, Amortized Cost	9,587	'
Cash, cash equivalents and available-for-sale investments, Gross Unrealized Gains	12	'
Cash, cash equivalents and available-for-sale investments, Estimated Fair Value	$9,599	'

Shortterm_Investments_Addition

Short-term Investments - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Investments Schedule [Abstract]	'	'	'	'
Investments with a maturity of greater than one year	$0	'	$0	'
Other-than-temporary impairment charges	$0	$0	$0	$0

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Summary of Cash, Cash Equivalents and Available-for-Sale Investments Measured at Fair Value on Recurring Basis (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	$53,617	$12,294
Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	53,617	12,294
Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	9,716	12,294
Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	43,901	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	'	'
Cash and Cash Equivalents [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	19,233	12,294
Short-term Investments [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	34,384	'
Cash [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	7,731	1,076
Cash [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	7,731	1,076
Cash [Member] | Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	7,731	1,076
Cash [Member] | Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	'	'
Cash [Member] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	'	'
Money Market Funds [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	1,985	11,218
Money Market Funds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	1,985	11,218
Money Market Funds [Member] | Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	1,985	11,218
Money Market Funds [Member] | Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	'	'
Money Market Funds [Member] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	'	'
Corporate Debt Securities [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	34,302	'
Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	34,302	'
Corporate Debt Securities [Member] | Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	34,302	'
Corporate Debt Securities [Member] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	'	'
Commercial Paper [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	9,599	'
Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	9,599	'
Commercial Paper [Member] | Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	9,599	'
Commercial Paper [Member] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]	'	'
Short-term investments	'	'

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Additional Information (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Oct. 31, 2013	Mar. 31, 2013	Feb. 28, 2013	Sep. 30, 2014
			Private Placement [Member]	Private Placement [Member]	Private Placement [Member]	Private Placement [Member]
			Series D convertible preferred stock [Member]	Series D convertible preferred stock [Member]	Series D convertible preferred stock [Member]	Series D convertible preferred stock [Member]
			Convertible Preferred Stock Financing Option [Member]	Convertible Preferred Stock Financing Option [Member]	Convertible Preferred Stock Financing Option [Member]	Convertible Preferred Stock Financing Option [Member]
Subsidiary, Sale of Stock [Line Items]	'	'	'	'	'	'
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	'	'	'	'
Annualized revenue rate over a trailing three month period	'	'	'	'	'	16,000,000
Financing liability	'	237,000	1,100,000	'	900,000	'
Additional convertible preferred stock shares issued	'	'	1,369,008	370,129	2,656,636	'
Net proceeds from issuance of convertible preferred stock	'	'	9,400,000	2,500,000	18,200,000	'
Convertible preferred stock issued	'	'	'	'	'	'2013-10
Change in fair value charges	'	'	$200,000	'	'	'

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments - Schedule of Changes in Estimated Fair Value using Valuations Classified as Level 3 - Convertible Preferred Stock Warrant Liability (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013
Fair Value Disclosures [Abstract]	'	'	'		'
Beginning of the period	$429	$93	$237	[1]	$93
Issued	'	10	'		10
Exercised	'	'	-29		'
Expired	'	'	'		'
Reclassified to equity	-406	'	-406		'
Change in fair value	-23	'	198		'
End of the period	'	$103	'		$103
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Fair_Value_of_Financial_Instru5

Fair Value of Financial Instruments - Schedule of Fair Value Assumptions and Methodology (Detail) (USD $)	3 Months Ended		9 Months Ended		1 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2013	Feb. 28, 2013
	Convertible Preferred Stock Warrant Liability [Member]	Convertible Preferred Stock Warrant Liability [Member]	Convertible Preferred Stock Warrant Liability [Member]	Convertible Preferred Stock Warrant Liability [Member]	Series D Convertible Preferred Stock Financing Option [Member]	Series D Convertible Preferred Stock Financing Option [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'	'	'	'	'
Expected life (years)	'4 years	'2 years	'2 years	'3 years	'	'
Expected volatility	44.00%	50.00%	46.00%	57.00%	'	'
Risk-free interest rate	1.20%	0.30%	0.50%	0.40%	'	'
Dividend yield	0.00%	0.00%	0.00%	0.00%	'	'
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

Fair_Value_of_Financial_Instru6

Fair Value of Financial Instruments - Schedule of Changes in Estimated Fair Value using Valuations Classified as Level 3 - Convertible Preferred Stock Financing Option (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'	'	'	'
Beginning of the period	'	$971	'	'
Issued	'	'	'	885
Exercised	'	'	'	'
Expired	'	'	'	'
Change in fair value	'	126	'	212
End of the period	'	$1,097	'	$1,097

Recovered_Sheet1

Notes Receivable From Related Parties - Additional Information (Detail) (USD $)

9 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

31-May-13

Apr. 30, 2013

Sep. 30, 2014

Jan. 31, 2014

Jan. 31, 2013

Jan. 31, 2012

Sep. 30, 2014

Dec. 31, 2011

Dec. 31, 2013

Jan. 31, 2007

President And Chief Executive Officer [Member]

President And Chief Executive Officer [Member]

President And Chief Executive Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Minimum [Member]

Related Party Transaction [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Note issued to related party

'

'

'

$500,000

$500,000

'

'

'

'

'

'

'

$300,000

Liquidation event threshold representing total proceeds payable to the Company

'

'

'

'

'

200,000,000

'

'

'

'

'

'

'

Note receivable from related party

'

'

100,000

'

'

'

'

'

'

'

'

100,000

'

Payment of note received

'

'

'

'

'

'

'

'

'

'

0

'

'

Debt forgiveness term

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

Debt forgiveness amount

$100,000

$100,000

'

'

'

'

$100,000

$100,000

$100,000

'

'

'

'

Loan_And_Security_Agreement_Ad

Loan And Security Agreement - Additional Information (Detail) (USD $)

9 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2014

Aug. 31, 2014

Dec. 31, 2013

Aug. 31, 2014

Aug. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Aug. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Aug. 31, 2013

Silicon Valley Bank

Silicon Valley Bank

Tranche Two

Year One [Member]

Year Two [Member]

Year Three [Member]

Growth Capital Facility

Growth Capital Facility

Growth Capital Facility

Revolving Accounts Receivable Line of Credit [Member]

Revolving Accounts Receivable Line of Credit [Member]

Minimum [Member]

Silicon Valley Bank

Tranche One

Tranche Two

Silicon Valley Bank

Line of Credit Facility [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement

'

'

'

'

$12,000,000

'

'

'

'

$8,000,000

$4,000,000

$4,000,000

'

$4,000,000

Advances under loan and security agreement

'

900,000

1,400,000

0

'

'

'

'

'

'

'

'

'

'

Loan agreement expiry date

'

'

'

'

'

'

'

'

'

'

31-Oct-14

31-Mar-15

'

'

Loan and security agreement, terms

'Second $4.0 million tranche was contingent upon the Company achieving a trailing three-month revenue of at least $7.0 million.

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, interest rate description

'The interest rate would have been fixed at the time of advance and would have been the greater of 3.65% or the three-year U.S. Treasury note plus 3%.

'

'

'

'

'

'

'

'

'

'

'

'Interest would have been the greater of 4.25% or SVB Prime Rate plus 0.25%.

'

Trailing three-month revenue

'

'

'

'

'

$7,000,000

'

'

'

'

'

'

'

'

Loan and security agreement, amortization period

'30 months

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, Final Payment, Percentage of advanced amount

3.90%

'

'

'

'

'

'

'

'

'

'

'

'

'

Penalty on prepaid principal

'

'

'

'

'

'

2.00%

1.00%

0.00%

'

'

'

'

'

Line of credit, expiration period

'

'

'

'

'

'

'

'

'

'

'

'

'August 2016

'

Percentage of eligible accounts receivable

'

'

'

'

'

'

'

'

'

'

'

'

80.00%

'

Percentage of annual loan fee

5.10%

'

'

'

'

'

'

'

'

'

'

'

0.75%

'

Interest great percentage

'

'

'

'

'

'

'

'

'

'

'

'

'4.25

'

Percentage of prime rate plus

'

'

'

'

'

'

'

'

'

'

'

'

0.25%

'

Loan_And_Security_Agreement_Ad1

Loan And Security Agreement - Additional Information 2 (Detail) (USD $)	1 Months Ended	9 Months Ended
	Aug. 31, 2013	Sep. 30, 2014	Dec. 31, 2013
Class of Warrant or Right [Line Items]	'	'	'
Warrants exercisable for common stock shares	'	53,357	57,433
Warrant exercisable, percentage of advanced amounts	'	1.25%	'
Loan Agreement Warrants [Member]	'	'	'
Class of Warrant or Right [Line Items]	'	'	'
Warrants exercisable for common stock shares	'	5,803	5,803
Warrants granted for common stock shares	20,313	'	'
Percentage of total growth capital facility	0.50%	'	'
Aggregate exercise price of warrants	$40,000	'	'
Warrant exercise price per share	'	$6.89	$6.89
Initial fair value	$10,000	'	'
Class of warrant or right exercise price of warrants or rights description	'	'Aggregate exercise price of 0.5% of the total growth capital facility commitment, or $40,000.	'
Class of warrant or right contingent consideration arrangements description	'	'Following any draw-downs under the growth capital facility, the warrant would have become exercisable for additional shares of Series D convertible preferred stock equal to 1.25% of the advanced amounts under tranche one and two divided by $6.89.	'

Equipment_Loans_Additional_Inf

Equipment Loans - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Aug. 31, 2014	Dec. 31, 2013	Apr. 30, 2013	Sep. 30, 2012
Capital Leased Assets [Line Items]	'	'	'	'	'	'	'	'
Aggregate principal amount under loan facility	'	'	'	'	'	'	'	$2,000,000
Interest rate	5.10%	'	5.10%	'	'	'	'	'
Interest expense	6,000	21,000	36,000	67,000	'	'	'	'
Amount outstanding	'	'	'	'	900,000	1,400,000	'	'
Frequency of monthly payments	'	'	'36-month	'	'	'	'	'
Capital lease obligation	'	'	'	'	'	'	100,000	'
Capital Lease Obligations [Member]	'	'	'	'	'	'	'	'
Capital Leased Assets [Line Items]	'	'	'	'	'	'	'	'
Interest rate	14.88%	'	14.88%	'	'	'	'	'
Amount outstanding	$65,000	'	$65,000	'	'	$87,000	'	'
Frequency of monthly payments	'	'	'38-month	'	'	'	'	'

Equipment_Loans_Schedule_of_Fu

Equipment Loans - Schedule of Future Minimum Payments under Equipment Loans (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Leases [Abstract]	'	'
2014 (remaining)	$10	$761
2015	42	761
2016	21	21
Thereafter	'	'
Total minimum payments	73	1,543
Less: amount representing interest	-8	-91
Present value of future payments	65	1,452
Less: current portion	-35	-696
Non-current portion	30	756
Present value of future payments	$65	$1,452

Convertible_Preferred_Stock_Wa2

Convertible Preferred Stock Warrant Liability - Schedule of Warrants to Purchase Shares of Convertible Preferred Stock Outstanding and Exercisable (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Dec. 31, 2013	Mar. 31, 2007	Sep. 30, 2014	Dec. 31, 2013	Nov. 30, 2007	Sep. 30, 2014	Dec. 31, 2013	Aug. 31, 2013
In Thousands, except Share data, unless otherwise specified			Equipment Loan Warrant [Member]	Equipment Loan Warrant [Member]	Equipment Loan Warrant [Member]	Venture Loan [Member]	Venture Loan [Member]	Venture Loan [Member]	Loan Origination Commitments [Member]	Loan Origination Commitments [Member]	Loan Origination Commitments [Member]
Class of Warrant or Right [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Initial Value	'	'	'	'	$4	'	'	$63	'	'	$10
Dates, Issuance	'	'	'2007-03	'	'	'2007-11	'	'	'2013-08	'	'
Dates, Expiration	'	'	'2014-03	'	'	'2017-11	'	'	'2023-08	'	'
In Connection With	'	'	'Equipment loan	'	'	'Venture loan	'	'	'Loan Agreement	'	'
Series	'	'	'A	'	'	'A	'	'	'D	'	'
Exercise Price	'	'	$3.68	$3.68	'	$3.68	$3.68	'	$6.89	$6.89	'
Shares Outstanding	53,357	57,433	'	4,076	'	47,554	47,554	'	5,803	5,803	'
Fair Value at	'	$237	'	$17	'	'	$200	'	'	$20	'

Convertible_Preferred_Stock_Wa3

Convertible Preferred Stock Warrant Liability - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended			9 Months Ended		1 Months Ended	9 Months Ended
	Jul. 31, 2014	Sep. 30, 2014	Dec. 31, 2013		Sep. 30, 2014	Sep. 30, 2013	Aug. 31, 2013	Sep. 30, 2014	Dec. 31, 2013
					Equipment Loan Warrant [Member]	Equipment Loan Warrant [Member]	Loan Agreement Warrants [Member]	Loan Agreement Warrants [Member]	Loan Agreement Warrants [Member]
Class of Warrant or Right [Line Items]	'	'	'		'	'	'	'	'
Number of shares of Series A convertible preferred stock exercised though a cashless exercise of warrants	'	'	'		4,076	'	'	'	'
Net preferred stock shares issued	'	0	0	[1]	2,431	'	'	'	'
Shares withheld due to exercise price	'	0	0	[1]	1,645	'	'	'	'
Number of shares of Series A convertible preferred stock exercised though exercise of warrants	'	'	'		'	22,418	'	'	'
Warrants exercise price per share	'	'	'		'	$3.68	'	$6.89	$6.89
Minimum proceeds from next financing	'	'	'		'	'	'	$5,000,000	'
Aggregate exercise price of warrants	'	'	'		'	'	40,000	'	'
Percentage of total growth capital facility	'	'	'		'	'	0.50%	'	'
Warrants expiry date	'	'	'		'	'	'	'2023-08	'
Shares Outstanding	'	53,357	57,433		'	'	'	5,803	5,803
Warrants expiration description	'	'	'		'	'	'	'Or upon the occurrence of an acquisition of the Company in exchange for cash or marketable securities	'
Reclassification of redeemable convertible preferred stock warrant liability to additional paid-in capital	$400,000	$400,000	'		'	'	'	'	'
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Convertible_Preferred_Stock_Wa4

Convertible Preferred Stock Warrant Liability - Additional Information (Parenthetical) (Detail) (USD $)	1 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Jul. 31, 2014	Sep. 30, 2014
Equity [Abstract]	'	'
Reclassification of redeemable convertible preferred stock warrant liability to additional paid-in capital	$0.40	$0.40

Convertible_Preferred_Stock_Su

Convertible Preferred Stock - Summary of Convertible Preferred Stock (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Class of Stock [Line Items]	'	'
Convertible preferred stock, shares authorized	0	15,907,322	[1]
Convertible preferred stock, Shares Issued	0	15,701,444	[1]
Convertible preferred stock, shares outstanding	0	15,701,444	[1]
Convertible preferred stock, Carrying Value	'	$90,760
Series A convertible preferred stock [Member]	'	'
Class of Stock [Line Items]	'	'
Convertible preferred stock, shares authorized	'	2,796,259
Convertible preferred stock, Shares Issued	'	2,744,619
Convertible preferred stock, shares outstanding	'	2,744,619
Convertible preferred stock, Carrying Value	'	9,987
Series B convertible preferred stock [Member]	'	'
Class of Stock [Line Items]	'	'
Convertible preferred stock, shares authorized	'	3,249,662
Convertible preferred stock, Shares Issued	'	3,249,657
Convertible preferred stock, shares outstanding	'	3,249,657
Convertible preferred stock, Carrying Value	'	19,894
Series C convertible preferred stock [Member]	'	'
Class of Stock [Line Items]	'	'
Convertible preferred stock, shares authorized	'	5,311,401
Convertible preferred stock, Shares Issued	'	5,311,395
Convertible preferred stock, shares outstanding	'	5,311,395
Convertible preferred stock, Carrying Value	'	30,521
Series D convertible preferred stock [Member]	'	'
Class of Stock [Line Items]	'	'
Convertible preferred stock, shares authorized	'	4,550,000
Convertible preferred stock, Shares Issued	'	4,395,773
Convertible preferred stock, shares outstanding	'	4,395,773
Convertible preferred stock, Carrying Value	'	$30,358
[1]	Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.

Convertible_Preferred_Stock_Ad

Convertible Preferred Stock - Additional Information (Detail) (USD $)	Dec. 31, 2013	Oct. 31, 2013	Mar. 31, 2013	Feb. 28, 2013	Sep. 30, 2014	Mar. 31, 2013
		Series D convertible preferred stock [Member]	Series D convertible preferred stock [Member]	Series D convertible preferred stock [Member]	Series D convertible preferred stock [Member]	Series D convertible preferred stock [Member]
		Private Placement [Member]	Private Placement [Member]	Private Placement [Member]	Private Placement [Member]	Employee [Member]
		Convertible Preferred Stock Financing Option [Member]	Convertible Preferred Stock Financing Option [Member]	Convertible Preferred Stock Financing Option [Member]	Convertible Preferred Stock Financing Option [Member]	Convertible Preferred Stock Financing Option [Member]
Subsidiary, Sale of Stock [Line Items]	'	'	'	'	'	'
Total net cash proceeds from initial closing	'	$9,400,000	$2,500,000	$18,200,000	'	$500,000
Preferred stock, shares issued	'	1,369,008	370,129	2,656,636	'	72,548
Annualized revenue rate over a trailing three-month period	'	16,000,000	'	'	'	'
Financing liability	237,000	1,100,000	'	900,000	'	'
Convertible preferred stock expired	'	'	'	'	'2013-10	'
Change in fair value charges	'	$200,000	'	'	'	'

Convertible_Preferred_Stock_Ad1

Convertible Preferred Stock - Additional Information (Parenthetical) (Detail) (Common Stock [Member], USD $)	1 Months Ended
In Millions, except Share data, unless otherwise specified	Jul. 31, 2014
Common Stock [Member]	'
Subsidiary, Sale of Stock [Line Items]	'
Convertible preferred stock was converted to common stock	'One-for-one
Convertible preferred stock was converted into common stock	15,703,875
Redeemable convertible preferred stock reclassified to common stock and additional paid-in capital	$90.80

Stockholders_Equity_Additional

Stockholder's Equity - Additional Information (Detail) (USD $)	9 Months Ended		12 Months Ended	1 Months Ended	9 Months Ended				0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Jul. 23, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Jul. 23, 2014	Jul. 23, 2014
				2014 Equity Incentive Plan [Member]	2014 Equity Incentive Plan [Member]	2014 Equity Incentive Plan [Member]	2013 Equity Incentive Plan [Member]	2013 Equity Incentive Plan [Member]	2014 Employee Stock Purchase Plan [Member]	2014 Employee Stock Purchase Plan [Member]
						Incentive Stock Option [Member]
Class of Stock [Line Items]	'	'	'	'	'	'	'	'	'	'
Shares reserved for issuance	'	'	'	4,750,000	'	'	'	'	'	496,092
Percentage of shares outstanding	'	'	'	3.00%	'	'	'	'	1.00%	'
Maximum number of shares to be issued	'	'	'	10,000,000	'	'	'	'	'	'
Price of options granted, percentage	'	'	'	'	'	100.00%	'	'	'	'
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.	'	'	'	'	'
Expiry period of options granted	'	'	'	'	'5 years	'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.	'	'	'	'
Options issued, vested	'	'	'	'	'	'	10,000	0	'	'
Options outstanding	2,308	'	1,928	'	'	'	600,000	'	'	'
Aggregate pre-tax intrinsic value of options outstanding and exercisable	$19,800,000	'	'	'	'	'	'	'	'	'
Aggregate pre-tax intrinsic value of options outstanding	27,100,000	'	'	'	'	'	'	'	'	'
Aggregate pre-tax intrinsic value of options exercised	1,400,000	300,000	'	'	'	'	'	'	'	'
Cash received on exercise of options	200,000	600,000	'	'	'	'	'	'	'	'
Options exercised with unvested shares	'	'	69,037	'	'	'	'	'	'	'
Repurchase rights held at original issuance price	36,898	'	53,796	'	'	'	'	'	'	'
Related liability	$33,000	'	$31,000	'	'	'	'	'	'	'

Stockholders_Equity_Summary_of

Stockholder's Equity - Summary of Stock Option Activity (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Options price, outstanding, beginning of period	$1.08
Options price, granted	$11.44
Options price, exercised	$1.43
Options price, forfeited	$1.47
Options price, expired	'
Options price, outstanding, end of period	$3.82
Options price, vested and expected to vest	$3.57
Options price, exercisable	$2.41
Options outstanding, beginning of period	1,928
Options granted	622
Options exercised	-153
Options forfeited	-89
Options expired	'
Options outstanding, end of period	2,308
Options vested and expected to vest	2,302
Options exercisable	1,514

StockBased_Compensation_Expens2

Stock-Based Compensation Expense - Summary of Stock Based Compensation Recognized Before Taxes (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$441	$113	$1,010	$243
Cost of Sales [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	14	6	36	14
Selling, General and Administrative Expenses [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	390	84	870	169
Research and Development Expense [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$37	$23	$104	$60

StockBased_Compensation_Expens3

Stock-Based Compensation Expense - Additional Information (Detail) (USD $)

0 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Apr. 30, 2013

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Apr. 30, 2013

Sep. 30, 2014

Feb. 28, 2011

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Apr. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Promissory Notes [Member]

Consultants [Member]

Consultants [Member]

Consultants [Member]

Consultants [Member]

Consultants [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Performance-Based Options February 2011 [Member]

Performance-Based Options February 2011 [Member]

Performance-Based Options February 2011 [Member]

Performance-Based Options February 2011 [Member]

Performance-Based Options February 2011 [Member]

Performance-Based Options April 2013 [Member]

Performance-Based Options April 2013 [Member]

Performance-Based Options April 2013 [Member]

Performance-Based Options April 2013 [Member]

Performance-Based Options April 2013 [Member]

President And Chief Executive Officer [Member]

Promissory Notes [Member]

Consultants [Member]

Promissory Notes [Member]

Consultants [Member]

President And Chief Executive Officer [Member]

President And Chief Executive Officer [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unearned stock-based compensation

'

$3,500,000

'

$3,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted average period for unearned stock-based compensation to be recognized

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options modified to permit exercise with promissory notes

'

'

'

'

'

500,000

'

'

'

'

'

'

'

500,000

'

'

'

'

'

'

'

'

'

'

'

Liquidation event threshold representing total proceeds payable to the Company

'

'

'

'

'

'

'

'

'

'

'

200,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of options to grant restricted stock

'

'

'

600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vesting period

'

'

'

'4 years

'

'

'

'

'

'

'

'

'5 months

'

'3 years

'4 years

'

'

'

'

'4 years

'

'

'

'

Incremental cost of modification

'

'

'

300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Incremental cost recognized

'

13,000

21,000

200,000

29,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unamortized modification cost related to vested options

'

'

'

200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Remaining unamortized cost yet to be amortized

'

100,000

'

100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options granted

'

'

'

622

'

'

'

0

'

0

'

'

'

'

'

289,253

'

'

'

'

363,000

'

'

'

'

Stock-based compensation expense

'

$441,000

$113,000

$1,010,000

$243,000

'

'

$51,000

$2,000

$100,000

$5,000

'

'

'

'

'

$4,000

$7,000

$13,000

$22,000

'

$19,000

$29,000

$100,000

$51,000

Shares purchased by non-employees

'

'

'

'

'

'

5,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average exercise price of options issued

'

'

'

'

'

'

$1.20

'

$1.20

'

$1.20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

StockBased_Compensation_Expens4

Stock-Based Compensation Expense - Summary of Weighted Average Assumptions Used to Estimate Options Using Black-Scholes Model (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected life (years)	'6 years	'6 years	'6 years	'6 years
Expected volatility	56.00%	66.00%	58.00%	67.00%
Risk-free interest rate	1.80%	2.20%	1.90%	1.60%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted average fair value	$7.15	$0.72	$5.95	$0.72
Consultants [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Expected life (years)	'9 years	'9 years	'9 years	'9 years
Expected volatility	56.00%	66.00%	61.00%	66.00%
Risk-free interest rate	2.50%	2.80%	2.60%	2.40%
Dividend yield	0.00%	0.00%	0.00%	0.00%

Net_Loss_Per_Share_Additional_

Net Loss Per Share - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Loss allocated to participating securities	$0
Contractual obligation	$0

Net_Loss_Per_Share_Schedule_of

Net Loss Per Share - Schedule of Net Loss Per Share (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net loss	($5,885)	($4,099)	($14,676)	($13,737)
Weighted average common stock outstanding	18,217	1,718	7,343	1,363
Net loss per share, basic and diluted	($0.32)	($2.39)	($2)	($10.08)

Net_Loss_Per_Share_Schedule_of1

Net Loss Per Share - Schedule of Potentially Dilutive Securities Outstanding Excluded from the Computations of Diluted Weighted Average Shares Outstanding (Detail)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of diluted weighted average shares outstanding	2,361	16,265
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	2,308	1,876
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	'	14,332
Convertible Preferred Stock Warrant Liability [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	53	'

Net_Loss_Per_Share_Schedule_of2

Net Loss Per Share - Schedule of Potentially Dilutive Securities Outstanding Excluded from the Computations of Diluted Weighted Average Shares Outstanding (Parenthetical) (Detail) (Common Stock [Member])	1 Months Ended
	Jul. 31, 2014
Common Stock [Member]	'
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

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
			Facility		Facility
Commitments and Contingencies Disclosure [Abstract]	'	'	'	'	'
Number of leased facility	'	'	1	'	1
Operating lease period	'	'	'36 months	'	'
Operating lease, Date	'	'	'2012-03	'	'
Operating lease, Effective date	'	'	1-Jun-12	'	'
Operating lease extension period	'	'	'3 years	'	'
Renewal provision allowing the Company to extend lease, percentage	95.00%	'	95.00%	'	'
Lease agreement description	'	'	'Rental payments on operating leases are charged to expense on a straight-line basis over the period of the lease. The Company entered into this 36-month lease in March 2012, effective June 1, 2012, for a facility with larger production and office space. 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.	'	'
Rent expense	$0.30	$0.30	$1	$1.10	'
Commitments to suppliers for purchases	$0.70	'	$0.70	'	$0.50

Commitments_and_Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Annual Operating Lease Payments (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'	'
2014(remaining)	$235	$928
2015	390	390
Thereafter	'	'
Total	$625	$1,318

Related_Parties_Additional_Inf

Related Parties - Additional Information (Detail) (USD $)

9 Months Ended

1 Months Ended

12 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2013

Dec. 31, 2012

Mar. 31, 2009

Dec. 31, 2012

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Mar. 31, 2009

Apr. 30, 2013

Sep. 30, 2014

31-May-13

Apr. 30, 2013

Sep. 30, 2014

Jan. 31, 2014

Jan. 31, 2013

Jan. 31, 2012

Jan. 31, 2007

Sep. 30, 2014

Dec. 31, 2011

Dec. 31, 2013

Affiliated Entity [Member]

Affiliated Entity [Member]

Affiliated Entity [Member]

Affiliated Entity [Member]

Affiliated Entity [Member]

Affiliated Entity [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Patents

Minimum [Member]

Warrant [Member]

Warrant [Member]

President And Chief Executive Officer [Member]

President And Chief Executive Officer [Member]

President And Chief Executive Officer [Member]

President And Chief Executive Officer [Member]

President And Chief Executive Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Chief Operating Officer [Member]

Maximum [Member]

Minimum [Member]

Related Party Transaction [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options modified to permit exercise with promissory notes

'

'

'

'

'

'

'

'

'

'

'

'

$500,000

'

'

$500,000

'

'

'

'

'

'

'

'

Note issued to related party

'

'

'

'

'

'

'

'

'

'

'

'

500,000

'

500,000

'

'

'

'

'

300,000

'

'

'

Liquidation event threshold representing total proceeds payable to the Company

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

200,000,000

'

'

'

'

'

'

'

Terms of related party transaction description

'

'

'

'

'

'

'

'

'

'

'

'

'

'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 Companybs 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 Companybs 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 entire principal amount and all accrued and unpaid interest of the loan was forgiven in full in June 2014. The full recourse promissory notes were secured by a pledge of the exercised shares.

'

'

'

'

'

'

'Pursuant to the terms of the promissory note, provided Mr. Kaufman remained a continuous, full-time employee of the Company, repayment of the notes was to begin after the third year of employment when 50% of Mr. Kaufman's annual bonus would have been applied to the loan balance until the loan was paid in full. The note was to mature and become immediately due and payable within 30 days following the date on which Mr. Kaufman ceased, voluntarily or involuntarily, to be employed by the Company.

'

'

'

Payment of note received

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

Debt forgiveness amount

100,000

100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100,000

100,000

100,000

'

'

'

'

Debt forgiveness term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

Note receivable from related party

'

'

'

100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100,000

Milestone payments upon execution of agreement

'

'

'

'

'

'

40,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Additional milestone payments

'

'

'

'

'

'

35,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares Outstanding

53,357

'

'

57,433

'

'

'

'

'

'

'

47,350

'

'

'

'

'

'

'

'

'

'

'

'

Warrant to purchase common stock per share value

'

'

'

'

'

'

'

'

'

'

'

$1

'

'

'

'

'

'

'

'

'

'

'

'

Number of irrigation tool patents purchased

'

'

'

'

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrant vested upon grant, Expiration date

'

'

'

'

'

'

'

'

'

'

7-Apr-19

'

'

'

'

'

'

'

'

'

'

'

'

'

Value of warrant at the date of grant

'

103,000

429,000

237,000

[1]

93,000

93,000

30,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Additional cash payments due upon achievement of net sales

'

'

'

'

'

'

'

'

80,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash payment

'

'

'

'

'

'

'

35,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Threshold of net sales of products incorporating technology, that triggers a cash payment

'

'

'

'

'

'

'

'

'

$1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Amounts have been derived from the December 31, 2013 audited financial statements included in the Company's registration statement on Form S-1 (No. 333-196974) filed with the Securities and Exchange Commission.