Revance Therapeutics (RVNC) 10-K 4 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Feb. 28, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Entity Registrant Name	Revance Therapeutics, Inc.
Entity Central Index Key	1479290
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		23,934,832
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$466.40

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS
Cash and cash equivalents	$171,032	$3,914
Restricted cash, current portion	75	75
Prepaid expenses and other current assets	1,624	825
Total current assets	172,731	4,814
Property and equipment, net	19,274	14,315
Restricted cash, net of current portion	435	510
Other non-current assets	29	3,006
TOTAL ASSETS	192,469	22,645
CURRENT LIABILITIES
Accounts payable	3,149	5,526
Accruals and other current liabilities	4,145	4,161
Deferred revenue, current portion	0	83
Derivative liabilities associated with convertible notes, current portion	0	4,890
Derivative liabilities associated with Medicis settlement, current portion	0	6,684
Financing obligation, current portion	307	0
Convertible notes, current portion	0	12,157
Notes payable, current portion and discount	2,635	10,702
Common stock warrant liability	0	3,358
Total current liabilities	10,236	47,561
Convertible preferred stock warrant liability	0	1,233
Financing obligation, net of current portion	598	0
Note payable, net of current portion and discount	0	2,632
Derivative liabilities associated with Medicis settlement, net of current portion	1,541	1,610
Deferred rent	3,725	3,176
TOTAL LIABILITIES	16,100	56,212
Commitments and Contingencies (Note 10)
Convertible preferred stock, par value $0.001 per share — 5,000,000 and 145,010,269 shares authorized as of December 31, 2014 and 2013, respectively; 0 and 8,689,999 shares issued and outstanding as of December 31, 2014 and 2013, respectively (aggregate liquidation preference of $0 and $215,264 as of December 31, 2014 and 2013, respectively)	0	123,982
STOCKHOLDERS’ EQUITY (DEFICIT)
Common stock, par value $0.001 per share — 95,000,000 and 224,000,000 shares authorized as of December 31, 2014 and 2013, respectively; 23,774,465 and 260,789 shares issued and outstanding as of December 31, 2014 and 2013, respectively	24	0
Additional paid-in capital	435,142	38,331
Accumulated deficit	-258,797	-195,880
TOTAL STOCKHOLDERS’ EQUITY (DEFICIT)	176,369	-157,549
TOTAL LIABILITIES, CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY (DEFICIT)	$192,469	$22,645

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Par value (in dollars per share)	$0.00	$0.00
Convertible preferred stock, shares authorized (in shares)	5,000,000	145,010,269
Convertible preferred stock, shares issued (in shares)	0	8,689,999
Convertible preferred stock, shares outstanding (in shares)	0	8,689,999
Aggregate liquidation preference	$0	$215,264
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized (in shares)	95,000,000	224,000,000
Common stock, shares issued (in shares)	23,774,465	260,789
Common stock, shares outstanding (in shares)	23,774,465	260,789

Consolidated_Statement_of_Oper

Consolidated Statement of Operations and Comprehensive Loss (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Revenue	$383	$617	$717
Operating expenses:
Research and development	33,390	27,831	32,708
Sales, general and administrative	19,043	11,011	11,195
Total operating expenses	52,433	38,842	43,903
Loss from operations	-52,050	-38,225	-43,186
Interest income	44	2	7
Interest expense	-10,672	-15,164	-28,959
Change in fair value of derivative liabilities associated with the convertible notes	4,032	2,660	13,860
Changes in fair value of derivative liabilities associated with Medicis settlement	-320	47	0
Change in fair value of common stock warrant liability	-2,151	-621	0
Change in fair value of convertible preferred stock warrant liability	-210	-743	125
Loss on settlement of preferred stock warrant	-1,356	0	0
Other expense, net	-234	-404	-106
Net and comprehensive loss	-62,917	-52,448	-58,259
Net income (loss) attributable to common stockholders (Note 15):
Basic	-62,917	258	-58,259
Diluted	($62,917)	$1,083	($58,259)
Net income (loss) per share attributable to common stockholders:
Basic (in dollars per share)	($3.24)	$1.17	($290.48)
Diluted (in dollars per share)	($3.24)	$1.05	($290.48)
Weighted-average number of shares used in computing net income (loss) per share attributable to common stockholders:
Basic (in shares)	19,391,523	220,220	200,560
Diluted (in shares)	19,391,523	1,029,150	200,560

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Convertible Preferred Stock and of Stockholders’ Equity (Deficit) (USD $)	Total	Series C-3	Series E-2	Series E-3	Series E-4	Series E-5	Series E-1 Convertible Preferred Stock	IPO	Common Stock	Common Stock	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member]
In Thousands, except Share data, unless otherwise specified										IPO		Series C-3	Series E-4	Series E-5	Series E-1 Convertible Preferred Stock	IPO			Series E-2	Series E-3	Series E-1 Convertible Preferred Stock
Beginning balance at Dec. 31, 2011	($155,482)								$0		$4,585						$0	($160,067)
Beginning balance at Dec. 31, 2011	95,433
Beginning balance (in shares) at Dec. 31, 2011	1,517,381
Beginning balance (in shares) at Dec. 31, 2011									198,499
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense related to stock-based compensation	79										79
Issuance of common stock warrants	153										153
Issuance of common stock upon exercise of stock options (in shares)									2,530
Issuance of common stock upon exercise of stock options	6										6
Issuance common stock (in shares)									2,995
Issuance of common stock upon exercise of warrants	1										1
Series C-3 convertible preferred stock modification		-3,225										-3,225
Net loss	-58,259																	-58,259
Ending balance at Dec. 31, 2012	-216,727								0		1,599						0	-218,326
Ending balance at Dec. 31, 2012	95,433
Ending balance (in shares) at Dec. 31, 2012	1,517,381
Ending balance (in shares) at Dec. 31, 2012									204,024
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock	11,256					36,375	-11,256														11,256
Issuance of convertible preferred stock (in shares)				607,476	4,748,484	1,810,441
Conversion of convertible preferred stock			-39,000	-24,638
Conversion of convertible debt					66,954
Issuance of convertible preferred stock as a deemed dividend (in shares)						7,911
Issuance of convertible preferred stock as a deemed dividend						177
Expiration of note payable from stockholder, Series E-1 (in shares)							-1,694
Expiration of note payable from stockholder, Series E-1							-63
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense related to stock-based compensation	548										548
Issuance of convertible preferred stock	11,256					36,375	-11,256														11,256
Conversion of convertible preferred stock			39,000	24,638															39,000	24,638
Conversion of convertible notes					32,008								32,008
Issuance of Series E-5 convertible preferred stock as a deemed dividend						-177								-177
Issuance of common stock warrants						4,272								4,272
Expiration of note payable from stockholder, Series E-1							63								63
Issuance of common stock upon exercise of stock options (in shares)									4,284
Issuance of common stock upon exercise of stock options	11										11
Issuance of common stock upon exercise of warrants	7										7
Issuance of common stock upon net exercise of warrant									52,481
Net loss	-52,448																	-52,448
Ending balance at Dec. 31, 2013	-157,549								0		38,331						0	-195,880
Ending balance at Dec. 31, 2013	123,982
Ending balance (in shares) at Dec. 31, 2013	8,689,999		585,559	1,150,341	4,748,468	1,818,390	387,241
Ending balance (in shares) at Dec. 31, 2013	260,789								260,789
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon net exercise of warrant									1,158,443
Ending balance at Jan. 31, 2014
Beginning balance at Dec. 31, 2013	-157,549								0		38,331						0	-195,880
Beginning balance at Dec. 31, 2013	123,982
Beginning balance (in shares) at Dec. 31, 2013	8,689,999
Beginning balance (in shares) at Dec. 31, 2013	260,789								260,789
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of preferred stock to common stock in connection with initial public offering (in shares)	-8,689,999
Conversion of preferred stock to common stock in connection with initial public offering	-123,982
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock and compensation expense relating to employee stock purchase plan (in shares)									25,339
Issuance of common stock relating to employee stock purchase plan	349										349
Stock-based compensation expense related to stock-based compensation	6,513										6,513
Conversion of preferred stock to common stock in connection with initial public offering (in shares)									8,689,999
Conversion of convertible preferred stock	123,981								9		123,972
Conversion of convertible notes	26,206								2		26,204
Issuance of common stock warrants	379							1,441			379					1,441
Issuance of common stock upon exercise of stock options (in shares)									239,000
Issuance of common stock upon exercise of stock options	1,422										1,422
Issuance common stock (in shares)									4,600,000	6,900,000
Issuance of common stock in connection with initial public offering, net of underwriting discounts, commissions and issuance costs of $11,800	131,335							98,644	5	7	131,330					98,637
Conversion of convertible notes (in shares)									1,637,846
Issuance of restricted stock awards, net of repurchase									251,325
Issuance of common stock upon net exercise of warrant									10,613
Issuance of common stock upon net exercise of common stock warrants and related extinguishment of warrant liability in connection with initial public offering (in shares)									1,158,443
Issuance of common stock upon net exercise of common stock warrants and related extinguishment of warrant liability in connection with initial public offering	6,490								1		6,489
Issuance of common stock for services rendered (in shares)									1,111
Issuance of common stock for services rendered	17										17
Termination of repurchase rights related to vesting of common stock issued pursuant to early exercises	58										58
Net loss	-62,917																	-62,917
Ending balance at Dec. 31, 2014	176,369								24		435,142						0	-258,797
Ending balance at Dec. 31, 2014	$0
Ending balance (in shares) at Dec. 31, 2014	0
Ending balance (in shares) at Dec. 31, 2014	23,774,465								23,774,465

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Convertible Preferred Stock and of Stockholders’ Equity (Deficit) (Parenthetical) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Common stock issued, price per share (in dollars per share)	$15.45	$22.50	$2.55
Exercise price of warrants (in dollars per share)		$0.15	$1.15
Stock issuance costs	$9,000	$132
Common stock issued, exercise of stock options (in dollars per share)		$2.55
IPO
Stock issuance costs	$11,800

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	($62,917)	($52,448)	($58,259)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	2,051	1,881	1,777
Amortization of discount on debt and capital leases	1,250	4,128	7,427
Amortization of debt issuance cost	203	217	300
Revaluation of derivative liabilities associated with convertible notes	-4,032	-2,660	-13,860
Revaluation of derivative liabilities associated with the Medicis settlement	320	-47	0
Revaluation of common stock warrant liability	2,151	621	0
Revaluation of convertible preferred stock warrant liability	210	-425	-125
Extinguishment of warrant liability upon exercise of put option by warrant holder	1,356	0	0
Convertible preferred stock warrant modification remeasurement adjustment	0	1,168	0
Loss on extinguishment of 2013 Notes	8,331	0	0
Stock-based compensation expense	6,530	548	79
Interest on convertible notes converted to convertible preferred stock	0	9,220	18,830
Interest for 2013 Notes and Essex Notes upon issuance, non-cash	271	273	0
Capitalized interest	-972	-453	0
Fair value of common stock warrants issued	379	0	0
Effective interest on financing obligation	28	0	0
Modification of Series C-3 convertible preferred stock in accordance with Medicis settlement agreement	0	0	-3,225
Derivative liabilities recognized as result of Medicis settlement agreement	0	0	15,268
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	-999	422	-1,125
Other non-current assets	-1,621	-2,770	257
Accounts payable	-3,399	3,193	1,028
Accruals and other current liabilities	2,394	-3,915	2,976
Payments against Medicis liabilities	-7,073	-6,927	0
Deferred rent	549	133	238
Deferred revenue	-83	83	-10,500
Net cash used in operating activities	-55,073	-47,758	-38,914
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	-6,975	-6,477	-319
Change in restricted cash	75	75	75
Net cash used in investing activities	-6,900	-6,402	-244
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of common stock, net of deferred follow-on public offering costs	131,880	0	0
Proceeds from issuance of common stock, net of deferred initial public offering costs	102,672	0	0
Proceeds from issuance of convertible notes and notes payable	6,750	21,903	18,170
Principal payments made on capital leases and financing obligation	-228	-982	-1,154
Principal payments made on notes payable	-12,316	-7,594	-3,403
Proceeds from the exercise of stock options and employee stock purchase plan	1,771	11	6
Payments to settle warrants	-1,438	0	0
Proceeds from the exercise of common stock warrants	0	7	1
Proceeds from issuance of convertible preferred stock, net	0	40,646	0
Net cash provided by financing activities	229,091	53,991	13,620
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	167,118	-169	-25,538
CASH AND CASH EQUIVALENTS — Beginning of period	3,914	4,083	29,621
CASH AND CASH EQUIVALENTS — End of period	171,032	3,914	4,083
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest	1,182	1,590	2,302
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Conversion of Series E-1, E-2, E-3, E-4 and E-5 preferred stock into common stock	123,982	0	0
Conversion of 2013 Notes into common stock	26,206	0	0
Issuance of common stock upon net exercise of common stock warrants in connection with IPO	6,490	0	0
Fair value in excess of debt host for derivative liabilities associated with convertible notes	1,050	5,750	2,255
Deferred initial public offering costs	4,028	2,490	0
Deferred follow-on public offering costs	546	0	0
Conversion of preferred stock warrants to common stock warrants	1,441	0	0
Conversion of Essex Notes into financing obligations	1,095	0	0
Termination of stock option repurchase right	58	0	0
Capital contribution on the extinguishment of the prior convertible preferred stock	0	74,894	0
Capital contribution on the extinguishment of the 2011 Notes	0	32,008	0
Deemed dividend on issuance of Series E-5 convertible preferred stock	0	177	0
Issuance of common stock warrants in connection with Series E-5 convertible preferred stock financing	0	4,272	153
Issuance of common stock warrants in connection with the 2013 Notes	981	2,737	0
Property and equipment purchases included in accounts payable and accruals and other current liabilities	1,348	2,285	0
Issuance of convertible preferred stock warrants	80	139	0
Fair value of common stock warrants issued	$379	$0	$0

The_Company_and_Basis_of_Prese

The Company and Basis of Presentation	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company and Basis of Presentation	The Company and Basis of Presentation
	Revance Therapeutics, Inc., or the Company, was incorporated in Delaware on August 10, 1999 under the name Essentia Biosystems, Inc. The Company commenced operations in June 2002 and on April 19, 2005, changed its name to Revance Therapeutics, Inc. The Company is a clinical-stage specialty biopharmaceutical company focused on the development, manufacturing and commercialization of novel botulinum toxin products for multiple aesthetic and therapeutic indications. The Company is leveraging its proprietary portfolio of botulinum toxin type A compounds, combined with its patented TransMTS® peptide delivery system to address unmet needs in large and growing neurotoxin markets. The Company's proprietary TransMTS technology enables delivery of botulinum toxin type A through two novel dose formulations, topical product candidate RT001 and injectable product candidate RT002. The Company is pursuing clinical development for RT001 and RT002 in a broad spectrum of aesthetic and therapeutic indications. The Company holds worldwide rights for all indications of RT001, RT002 and our TransMTS technology platform.
	Since commencing operations in 2002, the Company has devoted substantially all of its efforts to identifying and developing product candidates for the aesthetics and therapeutic pharmaceutical markets, recruiting personnel and raising capital. The Company has devoted predominantly all of its resources to preclinical, clinical, and manufacturing development of RT001 and RT002. The Company has never been profitable and has not yet commenced commercial operations.
	Since the Company's inception, the Company has incurred losses and negative cash flows from operations. The Company has not generated significant revenue from product sales to date and will continue to incur significant research and development and other expenses related to its ongoing operations. The Company has recorded net losses of $62.9 million, $52.4 million and $58.3 million for the years ended December 31, 2014, 2013 and 2012. As of December 31, 2014, the Company had a working capital surplus of $162.5 million and an accumulated deficit of $258.8 million. The Company has funded its operations primarily through the sale and issuance of common stock, convertible preferred stock, notes payable, and convertible notes. As of December 31, 2014, the Company had capital resources consisting of cash and cash equivalents of $171.0 million. The Company believes that its existing cash and cash equivalents will allow the Company to fund its operating plan through at least the next 12 months.
	Initial Public Offering
	In February 2014, the Company completed its initial public offering, or IPO, pursuant to which the Company issued 6,900,000 shares of common stock at $16.00 per share, including the exercise of the underwriters’ over-allotment option to purchase 900,000 additional shares of common stock, and received net proceeds of $98.6 million, after underwriting discounts, commissions and other offering expenses. In addition, in connection with the completion of the Company’s IPO, all convertible preferred stock converted into common stock.
	Follow-On Public Offering
	In June 2014, the Company completed a follow-on public offering, pursuant to which the Company issued 4,600,000 shares of common stock at $30.50 per share, including the exercise of the underwriters’ over-allotment option to purchase 600,000 additional shares of common stock, and received net proceeds of $131.3 million, after underwriting discounts, commissions and other offering expenses.
	Reverse Stock Split
	In January 2014, the Company’s Board of Directors and stockholders approved an amended and restated certificate of incorporation effecting a 1-for-15 reverse stock split of the Company’s issued and outstanding shares of common stock and convertible preferred stock that was effective on February 3, 2014. 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 share and per share amounts included in the accompanying financial statements have been retroactively adjusted to reflect this reverse stock split.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies
	Basis of Presentation
	The consolidated financial statements of the Company include the Company’s accounts and those of its wholly-owned subsidiary, Revance Therapeutics Limited, and have been prepared in conformity with accounting principles generally accepted in the United States of America, or US GAAP. All significant intercompany transactions and balances have been eliminated during consolidation.
	Use of Estimates
	The preparation of consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Such management estimates include the fair value of common stock, stock-based compensation, fair value of convertible preferred stock and warrants, fair value of derivatives, and the valuation of deferred tax assets. The Company bases its estimates on historical experience and also on assumptions that it believes are reasonable, however, actual results could significantly differ from those estimates.
	Risks and Uncertainties
	The product candidates developed by the Company require approvals from the U.S. Food and Drug Administration (FDA) or foreign regulatory agencies prior to commercial sales. There can be no assurance that the Company’s current and future product candidates will meet desired efficacy and safety requirements to obtain the necessary approvals. If the Company is denied approval or approval is delayed, it may have a material adverse impact on the Company’s business and its consolidated financial statements.
	The Company is subject to risks common to companies in the development stage including, but not limited to, dependency on the clinical and commercial success of its product candidates, ability to obtain regulatory approval of its product candidates, the need for substantial additional financing to achieve its goals, uncertainty of board adoption of its approved products, if any, by physicians and consumers, significant competition and untested manufacturing capabilities.
	Concentration of Credit Risk
	Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents. Under the Company's Investment Policy, the Company limits its credit exposure by investing in highly liquid funds with high credit quality. The Company’s cash and cash equivalents are held in the United States of America. Such deposits may, at times, exceed federally insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents.
	Cash and Cash Equivalents
	The Company considers all highly liquid investment securities with remaining maturities at the date of purchase of three months or less to be cash equivalents. Cash and cash equivalents include deposit and money market funds.
	Restricted Cash
	Deposits of $510,000 and $585,000 were restricted from withdrawal as of December 31, 2014 and 2013. The restriction is related to securing the Company’s facility lease and expires in 2025 in accordance with the operating lease agreement, as amended. The restrictions on these balances are being released at a rate of $75,000 per year until the balance is $400,000 and then remain at that limit until the end of the lease. These balances are included in restricted cash on the accompanying consolidated balance sheets.
	Fair Value of Financial Instruments
	The Company uses fair value measurements to record fair value adjustments to certain financial and non-financial assets and liabilities to determine fair value disclosures. The accounting standards define fair value, establish a framework for measuring fair value, and require disclosures about fair value measurements. Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required to be recorded at fair value, the principal or most advantageous market in which the Company would transact are considered along with assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance. The accounting standard for fair value establishes a fair value hierarchy based on three levels of inputs, the first two of which are considered observable and the last unobservable, that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement.
	The three levels of inputs that may be used to measure fair value are as follows:
		Level 1	—	Observable inputs, such as quoted prices in active markets for identical assets or liabilities.
		Level 2	—	Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
		Level 3	—	Valuations based on unobservable inputs to the valuation methodology and including data about assumptions market participants would use in pricing the asset or liability based on the best information available under the circumstances.
	Property and Equipment, Net
	Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Computer equipment and lab equipment is depreciated over 3 and 5 years, respectively. Prior to 2014, furniture and fixtures were depreciated over 7 years, however, the Company revised its estimate to 5 years for all assets in this category beginning in 2014. Additionally, prior to 2014, manufacturing equipment was depreciation over 5 years, however, the Company revised its estimate to 7 years for all assets in this category beginning in 2014. Repairs and maintenance that do not extend the life or improve an asset are expensed in the period incurred.
	Leasehold improvements are amortized over the lesser of 15 years or the term of the lease. Repairs and maintenance are charged to operations as incurred. When assets are retired or otherwise disposed of, the costs and accumulated depreciation are removed from the consolidated balance sheets and any resulting gain or loss is reflected in the consolidated statements of operations and comprehensive loss in the period realized.
	Impairment of Long-Lived Assets
	The Company evaluates its long-lived assets for indications of possible impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amounts to the future undiscounted cash flows, attributable to these assets. Should impairment exist, the impairment would be measured by the amount by which the carrying amount of the assets exceeds the projected discounted future cash flows arising from those assets. There have been no such impairments of long-lived assets as of and for the years ended December 31, 2014, 2013, and 2012.
	Clinical Trial Accruals
	Clinical trial costs are charged to research and development expense as incurred. The Company accrues for expenses resulting from obligations under contracts with clinical research organizations (CROs) and consultants, and under clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company’s objective is to reflect the appropriate expense in the consolidated financial statements by matching the appropriate expenses with the period in which services and efforts are expended. In the event advance payments are made to a CRO, the payments will be recorded as a prepaid asset which will be amortized in accordance with the contractual terms. In addition to pass-through costs, the Company incurs costs in clinical trials in three distinct phases as follows:
	(i)	Start-up Phase — This phase includes the initial set-up of the clinical trial and usually occurs within a few months after the contract has been executed and includes costs which are expensed ratably over the start-up phase. Start-up phase activities include study initiation, site recruitment, regulatory applications, investigator meetings, screening, preparation, pre-study visits and training.
	(ii)	Site and Study Management Phase — This phase includes medical and safety monitoring, and patient administration and data management. These costs are usually calculated on a per patient basis and expensed ratably over the treatment period beginning on the date that the patient enrolls.
	(iii)	Close Down and Reporting Phase — This phase includes analyzing the data obtained and reporting results, which occurs after patients have ceased treatment and the database of information collected is locked. These costs are expensed ratably over the close down and reporting phase.
	The CRO contracts generally include pass-through fees including, but not limited to, regulatory expenses, investigator fees, travel costs and other miscellaneous costs, including shipping and printing fees. The Company determines accrual estimates through reports from and discussion with clinical personnel and outside services providers as to the progress or state of completion of trials, or the services completed. The Company estimates accrued expenses as of each balance sheet date in the consolidated financial statements based on the facts and circumstances known to the Company at that time. The Company’s clinical trial accrual is dependent, in part, upon the receipt of timely and accurate reporting from the CROs and other third party vendors.
	Revenue
	The Company recognizes revenue when the following criteria are met: persuasive evidence of a sales arrangement exists; delivery has occurred; the price is fixed or determinable; and collectability is reasonably assured.
	In August 2011, the Company entered into an asset purchase and royalty agreement for the sale of the Relastin product line for $0.05 million and royalties on future sales of Relastin. Accordingly, under the Relastin asset purchase agreement, the Company recognized royalty revenue of $0.3 million during each of the years ended December 31, 2014, 2013, and 2012 and $0.2 million in milestone revenue in the year ended December 31, 2013 for achievement of a one-time milestone.
	License revenue during the years ended December 31, 2014, 2013, and 2012 resulted from a nonrefundable technology license fee which was deferred and recognized over the estimated period of performance. The Company estimated the performance period as the remaining life of the underlying patent at the inception of the license agreement, which was periodically reevaluated. License revenue for the year ended December 31, 2014 resulted from a nonrefundable technology access fee pursuant to an exclusive technology evaluation agreement. The Company received an upfront payment of $0.3 million, which was deferred and recognized over the estimated performance period.
	Research and Development Expenditures
	Research and development costs are charged to operations as incurred. Research and development costs include, but are not limited to, payroll and personnel expenses, clinical trial supplies, fees for clinical trial services, consulting costs and allocated overhead, including rent, equipment, depreciation and utilities. Research and development costs during the year ended December 31, 2012 also included the fair value of technology rights returned to the Company as a result of the Medicis settlement (Note 4).
	Income Taxes
	The Company accounts for income taxes under the asset and liability method. The Company estimates actual current tax exposure together with assessing temporary differences resulting from differences in accounting for reporting purposes and tax purposes for certain items, such as accruals and allowances not currently deductible for tax purposes. These temporary differences result in deferred tax assets and liabilities, which are included in the Company’s consolidated balance sheets. In general, deferred tax assets represent future tax benefits to be received when certain expenses previously recognized in the Company’s consolidated statements of operations and comprehensive loss become deductible expenses under applicable income tax laws or when net operating loss or credit carryforwards are utilized. Accordingly, realization of the Company’s deferred tax assets is dependent on future taxable income against which these deductions, losses and credits can be utilized.
	The Company must assess the likelihood that the Company’s deferred tax assets will be recovered from future taxable income, and to the extent the Company believes that recovery is not likely, the Company establishes a valuation allowance. Based on the available evidence, the Company is unable, at this time, to support the determination that it is more likely than not that its deferred tax assets will be utilized in the future. Accordingly, the Company recorded a full valuation allowance as of December 31, 2014 and 2013. The Company intends to maintain valuation allowances until sufficient evidence exists to support its reversal.
	Stock-Based Compensation
	The Company has equity incentive plans under which various types of equity-based awards, including incentive stock options, nonqualified stock options, and restricted stock awards, may be granted to employees and nonemployee consultants. The Company also has an inducement plan under which various types of equity-based awards, including nonqualified stock options and restricted stock awards, may be granted to new employees.
	For stock options granted to employees, the Company recognizes compensation expense for all stock-based awards based on the grant-date estimated fair values, net of an estimated forfeiture rate. For restricted stock awards to employees, the fair value is based on the closing price of the Company's common stock on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as expense ratably over the requisite service period. The fair value of stock options is determined using the Black-Scholes option pricing model. The Company estimates its forfeiture rate based on an analysis of its actual forfeitures and will continue to evaluate the adequacy of the forfeiture rate assumption based on actual forfeitures, analysis of employee turnover, and other related factors.
	Stock-based compensation expense related to stock options granted to nonemployees is recognized based on the fair value of the stock options, determined using the Black-Scholes option pricing model, as they are earned. The awards vest over the time period the Company expects to receive services from the nonemployee.
	Warrants
	The Company has issued freestanding warrants to purchase shares of common stock and convertible preferred stock in connection with certain debt and lease transactions. The warrants are recorded at fair value using the Black-Scholes option pricing model.
	Common Stock Warrants
	Prior to completion of the IPO, the Company accounted for warrants to purchase shares of its common stock in connection with the 2013 Notes as liabilities at fair value because these warrants may have obligated the Company to transfer assets to the holders at a future date under certain circumstances, such as change of control. The Company remeasured these warrants to current fair value at each balance sheet date, with changes in fair value recognized as a change in fair value of the warrant liability on the consolidated statements of operations and comprehensive loss. Upon completion of the IPO, these warrant liabilities were remeasured to fair value and settled in conjunction with a cashless net exercise of these warrants. Common stock warrants classified as equity at inception are recorded to additional paid-in capital at fair value upon issuance.
	Convertible Preferred Stock Warrants
	The Company accounted for previously outstanding warrants to purchase shares of its convertible preferred stock that are contingently redeemable as liabilities at their estimated fair value because these warrants obligated the Company to transfer assets to the holders at a future date under certain circumstances, such as a deemed liquidation event. The warrants were subject to remeasurement to fair value at each balance sheet date, with changes in fair value recognized as change in fair value of convertible preferred stock warrant liability on the consolidated statements of operations and comprehensive loss. Upon completion of the IPO, the convertible preferred stock warrants converted into equity-classified warrants to purchase shares of common stock.
	Derivative Liabilities
	The Company bifurcated and separately accounted for derivative instruments related to redemption and conversion features embedded within previously outstanding convertible notes and other derivative instruments related to payment provisions underlying the Medicis settlement. These derivatives are accounted for as liabilities, which will be remeasured to fair value as of each balance sheet date, with changes in fair value recognized in the Consolidated Statements of Operations and Comprehensive Loss. The derivative liabilities associated with the 2013 Convertible Notes are no longer outstanding due to the conversion of the related convertible notes upon the IPO in February 2014. The Company will continue to record adjustments to the fair value of the derivative liabilities associated with the Medicis settlement until the related settlement payments have been paid.
	Comprehensive Loss
	Comprehensive loss is defined as a change in equity of a business enterprise during a period, resulting from transactions from non-owner sources. There have been no material items qualifying as other comprehensive loss and, therefore, for all periods presented, the Company’s comprehensive loss was the same as its reported net loss.
	Net Income (Loss) per Share Attributable to Common Stockholders
	The Company calculates its basic and diluted net income (loss) per share attributable to common stockholders in conformity with the two-class method required for companies with participating securities. Under the two-class method, the Company determines whether it has net income attributable to common stockholders, which includes the results of operations, capital contributions and deemed dividends less current period convertible preferred stock non-cumulative dividends. If it is determined that the Company does have net income attributable to common stockholders during a period, the related undistributed earnings are then allocated between common stock and the convertible preferred stock based on the weighted average number of shares outstanding during the period to determine the numerator for the basic net income per share attributable to common stockholders. In computing diluted net income attributable to common stockholders, undistributed earnings are re-allocated to reflect the potential impact of dilutive securities to determine the numerator for the diluted net income per share attributable to common stockholders. The Company’s basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) by the weighted average number of shares of common stock outstanding for the period. The diluted net income (loss) per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. The diluted net income (loss) per share attributable to common stockholders also includes vested restricted stock awards and, if the effect is not anti-dilutive, unvested restricted stock awards. For purposes of this calculation, options to purchase common stock, restricted stock, and common stock warrants are considered common stock equivalents.
	Interest Expense
	Interest expense, includes cash and non-cash components with the non-cash components consisting of (i) interest recognized from the amortization of debt issuance costs, which were capitalized on the Consolidated Balance Sheets, that are generally derived from cash payments related to the issuance of convertible notes and notes payable, (ii) interest recognized from the amortization of debt discounts, which were capitalized on the Consolidated Balance Sheets, derived from the issuance of warrants and derivatives issued in conjunction with convertible notes and notes payable, (iii) interest recognized on the 2011 convertible notes, or 2011 Notes, which was not paid but instead converted into shares of convertible preferred stock, (iv) interest recognized on the 2013 convertible notes, or 2013 Notes, which was not paid but instead converted into shares of common stock, (v) interest capitalized for assets constructed for use in operations, (vi) interest related to the extinguishment of debt, which is classified as a gain or loss on debt extinguishments, and (vii) effective interest recognized on the financing obligation. The capitalized amounts related to the debt issuance costs and debt discounts are generally amortized to interest expense over the term of the related debt instruments.
	Recent Accounting Pronouncements
	In August 2014, the FASB issued Accounting Standard Update No. 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40), which will require management to assess an entity’s ability to continue as a going concern at each annual and interim period. Related footnote disclosures will be required if conditions give rise to substantial doubt about an entity’s ability to continue as a going concern within one year of the report issuance date. If conditions do not give rise to substantial doubt, no disclosures will be required specific to going concern uncertainties. The guidance defines substantial doubt using a likelihood threshold of “probable” similar to the current use of that term in U.S. GAAP for loss contingencies and provides example indicators. The guidance is effective for reporting periods ending after December 15, 2016, and early adoption is permitted. The Company is currently evaluating the impact of the adoption of this guidance on the Company’s financial statements.
	In June 2014, the FASB issued Accounting Standard Update No. 2014-10, Development Stage Entities (Topic 915): Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation, which removes the distinction between development stage entities and other reporting entities, eliminates the exception provided to development stage entities for determining whether an entity is a variable interest entity on the basis of the amount of investment equity that is at risk, and clarifies disclosure requirements related to risks and uncertainties. The changes eliminate the requirements for development stage entities to (1) present inception-to-date information on the statements of operations, cash flows, and stockholders’ equity, (2) label the financial statements as those of a development stage entity, (3) disclose a description of the development stage activities in which the entity is engaged, and (4) disclose in the first year in which the entity is no longer a development stage entity that the prior years it had been in the development stage. The Company evaluated the new guidance and adopted the new standard early, beginning with the quarterly period ended June 30, 2014.

License_Agreements

License Agreements	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License Arrangements	License Agreements
	In June 2013, the Company entered into an exclusive technology evaluation agreement with the Procter and Gamble Company to co-develop and explore applications of the TransMTS® delivery technology in two classes of over-the-counter cosmetic compounds. In connection with this agreement, the Company recognized license revenue of $0.1 million during the year ended December 31, 2014, and the Company received an upfront payment in the amount of $0.3 million, which was initially recorded as deferred revenue and is being recognized over the estimated performance period of 9 months. The Company recognized total license revenue of $0.1 million, $0.2 million, and $0.4 million during the years ended December 31, 2014, 2013, and 2012.
	In July 2009, the Company and Medicis Pharmaceutical Corporation, or Medicis, entered into a license agreement (License Agreement) granting Medicis worldwide aesthetic and dermatological rights to the Company’s investigational, injectable botulinum toxin type A product candidate in exchange for an upfront payment of $10.0 million plus additional milestone payments. Medicis was subsequently acquired by Valeant Pharmaceuticals International, Inc. in December 2012. The Company recognized these payments in the prior years as license revenue over the estimated performance period which was estimated as the remaining life of the underlying patent at the inception of the license agreement.
	In February 2007, the Company entered into a license and service agreement and a manufacturing and supply agreement with List Biological Laboratories, Inc. (List Laboratories), a developer of botulinum toxin. The agreement, as amended in April 2009, included certain milestone payments for the preparation of botulinum toxin and the development of the toxin manufacturing process as well as royalties from future sales of botulinum toxin. The Company expensed research and development costs associated with manufacturing for RT001 of $2.0 million for the year ended December 31, 2012 with no such costs in December 31, 2014 and 2013.

Medicis_Settlement

Medicis Settlement	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Medicis Settlement	Medicis Settlement
	In October 2012, the Company entered into a settlement and termination agreement with Medicis. The terms of the settlement provided for the reacquisition of the rights related to all territories of RT001 and RT002 from Medicis and for consideration payable by the Company to Medicis of up to $25.0 million, comprised of (i) an upfront payment of $7.0 million, which was paid in 2012, (ii) a Proceeds Sharing Arrangement Payment of $14.0 million due upon specified capital raising achievements by the Company, of which $6.9 million was paid in 2013 and the remaining $7.1 million was paid in 2014, and (iii) $4.0 million to be paid upon the achievement of specified regulatory milestones by the Company, or Product Approval Payment. Beginning on the third anniversary of the Settlement Date, any unpaid amount will begin to accrue interest at a rate of 8% per annum.
	The Company determined that the settlement provisions related to the Proceeds Sharing Arrangement Payment in (ii) above and Product Approval Payment in (iii) above were derivative instruments that require fair value accounting as a liability and periodic fair value remeasurements until settled.
	As of December 31, 2013, the Proceeds Sharing Arrangement Payment derivative was remeasured to fair value. The fair value of the Proceeds Sharing Arrangement Payment derivative as of December 31, 2013 of $6.7 million was determined using an option pricing model with the following assumption: expected term of 0.1-0.5 years, risk-free rate of 0.01% — 0.10% and volatility of 37.00% — 47.50%. Upon the completion of our IPO, we paid $7.1 million in settlement of our remaining obligation for the Proceeds Sharing Arrangement Payment. At the settlement date, the derivative liability was remeasured to the fair value of the obligation due, or $7.1 million, and the Company recorded $0.3 million to remeasure the fair value of the derivative for the remaining obligation through the date of settlement, or February 13, 2014.
	The fair value of the Product Approval Payment derivative as of December 31, 2013 in the amount of $1.6 million was determined by updating the estimate of the timing and probability of the related approval and a discount factor assuming a term of 3.25 years, a risk-free rate of 0.9% and a credit risk adjustment of 6.0%. As of December 31, 2014, the Company determined the fair value of its liability for the Product Approval Payment was $1.5 million, which was measured by assuming a term of 3.5 years, a risk-free rate of 1.2% and a credit risk adjustment of 6.5%. The Company’s assumption for the expected term is based on an expected Biologics License Application, or BLA, approval in mid-2018. The Company did not make any payments under the Product Approval Payment during the year ended December 31, 2014.
	As a result of the fair value measurements during the year ended December 31, 2014 and 2013, the Company recognized $0.3 million aggregate loss and $0.05 million aggregate gain, respectively.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	The Company measures and reports certain financial instruments as assets and liabilities at fair value on a recurring basis. These liabilities, consisting of derivative liabilities associated with convertible notes, derivative liabilities associated with the Medicis settlement, common stock warrant liabilities, and convertible preferred stock warrant liabilities, are considered Level 3 instruments. The fair value of these instruments was as follows (in thousands):
		December 31, 2014
		Fair Value			Level 1			Level 2			Level 3
	Assets
	Money market funds	$	166,038		$	166,038		$	—		$	—
	Total assets measured at fair value	$	166,038		$	166,038		$	—		$	—
	As of December 31, 2013, the Company did not hold any assets that were measured at fair value on a recurring basis.
		As of December 31, 2014
		Fair Value			Level 1			Level 2			Level 3
	Liabilities
	Derivative liabilities associated with the Medicis settlement	$	1,541		$	—		$	—		$	1,541
	Total liabilities measured at fair value	$	1,541		$	—		$	—		$	1,541
		As of December 31, 2013
		Fair Value			Level 1			Level 2			Level 3
	Liabilities
	Derivative liabilities associated with convertible notes	$	4,890		$	—		$	—		$	4,890
	Derivative liabilities associated with the Medicis settlement	8,294			—			—			8,294
	Common stock warrant liability	3,358			—			—			3,358
	Convertible preferred stock warrant liability	1,233			—			—			1,233
	Total liabilities measured at fair value	$	17,775		$	—		$	—		$	17,775
	The Company did not transfer any assets or liabilities measured at fair value on a recurring basis to or from Level 1 and Level 2 during the years ended December 31, 2014 and 2013.
	The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial instruments as follows (in thousands):
		Derivative			Derivative			Common			Convertible
		Liability			Liability			Stock Warrant			Preferred
		Associated with			Associated with			Liability			Stock Warrant
		Convertible			the Medicis						Liability
		Notes			Settlement
	Fair value as of December 31, 2012	$	1,800		$	15,268		$	—		$	351
	Fair value of financial instruments issued	5,750			—			2,737			139
	Payments against Medicis liabilities	—			(6,927		)	—			—
	Modification remeasurement	—			—			—			1,168
	Change in fair value	(2,660		)	(47		)	621			(425		)
	Fair value as of December 31, 2013	4,890			8,294			3,358			1,233
	Fair value of financial instruments issued	1,050			—			981			80
	Cash payments against Medicis liabilities	—			(7,073		)	—			—
	Change in fair value	(4,032		)	320			2,151			210
	Extinguishment of warrant liability upon exercise of put option by warrant holder	—			—			—			(82		)
	Balance upon conversion	(1,908		)	—			(6,490		)	(1,441		)
	Fair value as of December 31, 2014	$	—		$	1,541		$	—		$	—
	Level 3 instruments consist of the Company’s derivative liabilities related to convertible notes, derivative liabilities related to the Medicis settlement, common stock warrant liabilities, and convertible preferred stock warrant liabilities.
	The fair value of the derivative liabilities associated with the convertible notes was measured using the Monte Carlo valuation methodology (Note 8). Inputs used to determine estimated fair value of these derivative instruments include the probability estimates of potential settlement scenarios for the convertible notes, a present value discount rate and an estimate of the expected timing of settlement. The significant unobservable inputs used in the fair value measurement of the derivatives associated with the convertible notes are the scenario probabilities and the discount rate estimated at the valuation date. Generally, increases or decreases in the discount rate would result in a directionally opposite impact to the fair value measurement of this derivative instrument. Also, changes in the probability scenarios would have had varying impacts depending on the weighting of each specific scenario. As discussed further in Note 8, heavier weighting towards a change in control, a private investment in public equity transaction or IPO would result in an increase in fair value of this derivative instrument. The fair value upon the IPO took into account a 100% weighting towards the IPO scenario.
	The fair value of one of the derivative liabilities resulting from the Medicis litigation settlement, specifically the previously outstanding liability for the derivative related to the Proceeds Sharing Arrangement Payment (Note 4), was measured using an option pricing model (Note 8). Inputs used to determine estimated fair value of this derivative include the equity value of the Company, expected timing of the respective settlement payments, a risk-free interest rate and the expected volatility. The significant unobservable inputs used in the fair value measurement of the Proceeds Sharing Arrangement Payment derivative are the equity value of the Company and the expected timing of the payments at the valuation date. Generally, increases or decreases in these unobservable inputs would result in a directionally similar impact to the fair value measurement of this derivative instrument. The Company settled the remaining obligation under the Proceeds Sharing Arrangement upon the IPO, and remeasured the liability to the value of the remaining Proceeds Sharing Arrangement Payment of $7.1 million.
	The fair value of the remaining derivative liability resulting from the Medicis litigation settlement, specifically the derivative related to the Product Approval Payment (Note 4), was determined by estimating the timing and probability of the related regulatory approval and multiplying the payment amount by this probability percentage and a discount factor based primarily on the estimated timing of the payment and a credit risk adjustment (Note 4). The significant unobservable inputs used in the fair value measurement of the Product Approval Payment derivative are the expected timing and probability of the payments at the valuation date and the credit risk adjustment.
	The fair values of the outstanding common stock warrants and previously outstanding convertible preferred stock warrants were measured using the Black-Scholes option-pricing model (Note 13). Inputs used to determine estimated fair value of the warrant liabilities include the estimated fair value of the underlying stock at the valuation date, the estimated term of the warrants, risk-free interest rates, expected dividends and the expected volatility of the underlying stock. The significant unobservable inputs used in the fair value measurement of the convertible preferred stock warrant liability are the fair value of the underlying stock at the valuation date and the estimated term of the warrants.

Balance_Sheet_Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2014
Balance Sheet Components [Abstract]
Balance Sheet Components	Balance Sheet Components
	Property and Equipment, net
	Property and equipment, net consists of the following (in thousands):
		As of December 31,
		2014			2013
	Research equipment	$	10,914		$	9,045
	Computer equipment	477			496
	Furniture and fixtures	534			451
	Leasehold improvements	3,833			3,632
	Construction in progress	13,422			8,880
	Total property and equipment	29,180			22,504
	Less: accumulated depreciation and amortization	(9,906		)	(8,189		)
	Property and equipment, net	$	19,274		$	14,315
	Depreciation expense was $2.1 million, $1.9 million, and $1.8 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	As of December 31, 2014, the Company had obligations to make future payments to certain vendors that become due and payable during the construction of its manufacturing facilities in Newark, California. The arrangement was accounted for as construction-in-progress and the outstanding obligations as of December 31, 2014 and 2013 were $0.5 million and $1.8 million, respectively. The Company capitalized interest costs in the amount of $1.0 million and $0.5 million within construction-in-progress during the years ended December 31, 2014 and 2013, respectively. The Company did not capitalize interest costs during the year ended December 31, 2012.
	Prepaid Expenses and Other Current Assets
	Prepaid expenses and other current assets consist of the following (in thousands):
		As of December 31,
		2014			2013
	Prepaid expenses	$	1,085		$	531
	Accounts receivable	300			225
	Other current assets	239			69
	Total prepaid expenses and other current assets	$	1,624		$	825
	Accruals and Other Current Liabilities
	Accruals and other current liabilities consist of the following (in thousands):
		As of December 31,
		2014			2013
	Accrued compensation	$	2,088		$	689
	Accrued professional service fees	577			367
	Accrued manufacturing and quality control costs	361			—
	Accrued clinical trial expenses	322			169
	Accrued fixed assets	266			—
	Accrued construction-in-progress obligations	60			1,757
	Accrued interest on notes payable	23			478
	Accrued initial public offering costs	—			506
	Other current liabilities	448			195
	Total accruals and other current liabilities	$	4,145		$	4,161
	Other Non-Current Assets
	Other non-current assets consist of the following (in thousands):
		As of December 31,
		2014			2013
	Deferred initial public offering costs	$	—		$	2,812
	Unamortized debt issuance costs	—			194
	Prepaid expenses, non-current	$	29		$	—
	Total other non-current assets	$	29		$	3,006

Notes_Payable

Notes Payable	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Notes Payable	Notes Payable
	Hercules Notes Payable
	In September 2011, the Company entered into a loan and security agreement with Hercules Technology Growth Capital for $22.0 million, referred to as the Hercules Notes Payable. From the proceeds of the Hercules Notes Payable, the Company used $7.0 million to fully repay the principal and accrued interest due under two secured promissory notes, or Venture Debt, with two venture debt lenders. At the time of the Venture Debt repayment, the remaining unamortized debt discount of $579,000 was written-off to interest expense.
	The Hercules Notes Payable, which matures in March 2015, is collateralized by all assets of the Company, and bears interest at the greater of (i) 9.85% per annum or (ii) 9.85% per annum plus the difference of the prime rate less 3.25% per annum and contains covenants that require, among other things, that the Company seek consent from Hercules prior to certain corporate changes and provide certain unaudited financial information within 45 days after the end of each quarter. Starting in July 2012, the loan is to be repaid in 33 equal monthly payments of principal and interest of $0.8 million plus an end of term payment of $0.5 million if the loan is prepaid, or $0.4 million if paid upon maturity. The loan also allows for prepayment at any time with a premium ranging from 1% to 4% of $15.0 million, depending on when the prepayment occurs.
	In connection with the Hercules Notes Payable, the Company issued warrants to purchase 17,977 shares of Series D convertible preferred stock at $66.75 per share, which converted to warrants to purchase common stock upon the Company's IPO. The fair value of the warrants of $0.1 million was recorded as a debt discount and is amortized to interest expense using the straight-line method over the loan term. The Company recognized interest expense of $0.04 million, $0.1 million and $0.04 million from the amortization of the warrant related debt discount for the years ended December 31, 2014, 2013 and 2012, respectively. The unamortized debt discount balance was $0.01 million and $0.04 million as of December 31, 2014 and 2013, respectively. The Company incurred $0.5 million of debt issuance costs in connection with the Hercules Notes Payable which is also being amortized to interest expense over the term of the borrowings. The Company recognized interest expense of $0.2 million from the amortization of the debt issuance costs during each of the years ended December 31, 2014, 2013 and 2012, respectively. The unamortized debt issuance costs balances were $0.04 million and $0.2 million as of December 31, 2014 and 2013, respectively.
	As of December 31, 2014, future principal payments under the Hercules Notes Payable are as follows (in thousands):
	Year Ending December 31,
	2015	2,641
	Total principal payments	2,641
	Less: debt discount	(6		)
	Less: current portion	(2,635		)
	Long-term portion of notes payable	$	—
	The Company made principal and interest payments on the Hercules Notes Payable of $9.2 million during each of the years ended December 31, 2014 and 2013, respectively. As of December 31, 2014, the outstanding Hercules Notes Payable balance was $2.6 million.
	Essex Capital Notes
	On December 20, 2013, the Company signed a Loan and Lease Agreement to borrow up to $10.8 million in the form of Secured Promissory Notes from Essex Capital, or the Essex Notes, to finance the completion and installation of the Company’s RT001 commercial fill/finish line, or the Fill/Finish Line. Under the Loan and Lease Agreement, with the issuance of each Note the Company will issue warrants to purchase its capital stock. The Essex Notes incurred interest at 11.5% until the completion of the IPO in February 2014. Subsequent to the IPO, the notes incurred interest at 10.375% per annum. In December 2013, the Company drew down $2.5 million under short-term notes pursuant to the Essex Capital Facility, and an additional $2.5 million in January 2014 under short-term notes. In May 2014, pursuant to the terms of this agreement, the Company sold equipment to Essex Capital, resulting in partial settlement of the outstanding loan balance by $1.1 million. Pursuant to the Loan and Lease Agreement, the Company sold and leased the equipment back from Essex Capital. This transaction does not qualify for sale-leaseback accounting due to the Company’s continuing involvement. Therefore, the Company accounted for this transaction as a financing obligation using the effective interest rate method. As of December 31, 2014, the aggregate total future minimum lease payments under the financing obligation were as follows (in thousands):
	Year Ending December 31,
	2015	423
	2016	423
	2017	141
	Total payments	987
	On December 17, 2014, the Company entered into the First Amendment to the Loan and Lease Agreement with Essex Capital. Under the terms of this Amendment, the Company agreed to repay the outstanding debt balance of $3.9 million and issue a warrant to purchase 44,753 shares of common stock. In February 2015, the Company executed the Second Amendment to the Loan and Lease Agreement, under which the term of the facility was extended to April 15, 2015 and the purchase price of the equipment was increased by $0.1 million to approximately $9.8 million. Concurrently with this sale, the Company will lease the IMA Life equipment from Essex Capital for a fixed monthly payment to be paid monthly over 3 years. At the end of the lease the Company will have the option to purchase the leased equipment for 10% of the original purchase amount.
	In connection with the Essex Notes, the Company issued warrants to purchase 12,345 shares of Series E-5 convertible preferred stock in both December 2013 and January 2014. Subsequent to the February 2014 IPO, the previously issued warrants to purchase shares of Series E-5 convertible preferred stock converted into warrants to purchase shares of common stock. The fair value of the warrants at the issuance date of $0.2 million and debt issuance costs totaling $0.03 million were recorded as discount on debt, and will be amortized to interest expense using the straight-line method over the loan term. The Company recognized interest expense $0.2 million and $0.004 million for the amortization of the warrant related debt discount for the years ended December 31, 2014 and 2013, respectively. The unamortized debt discount balance was $0 million and $0.2 million as of December 31, 2014 and 2013, respectively.
	Additionally, the Company made interest payments on the Essex Notes in the amount of $0.4 million and $0 million for the years ended December 31, 2014 and 2013, respectively. In December 2014, the Company repaid the Essex Notes principal balance of $3.9 million in full.

Convertible_Notes_Warrants_and

Convertible Notes, Warrants, and Related Derivatives	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Convertible Notes, Warrants, and Related Derivatives	Convertible Notes, Warrants, and Related Derivatives
	2011 Convertible Notes and Common Stock Warrants
	In January 2011, the Company entered into a convertible promissory note agreement, or the 2011 Notes to borrow up to $15.0 million in 3 installments in the form of convertible debt. In May 2011, the Company amended the credit facility to modify the maturity date of the initial three installments and borrowed an additional amount of $30.0 million from new investors. Between September and December 2012, the Company completed three additional installments of 2011 Notes in the amount of $18.2 million. Of the 2011 Notes issued, an aggregate of $40.6 million were issued to related parties of which $30.9 million were issued to existing stockholders with holdings of 5% or more of the outstanding equity of the Company at the time of issuance. These holders were determined to be related parties because they include holders of convertible preferred stock and board members who can influence the conversion or redemption of the 2011 Notes.
	In conjunction with a Series E-5 convertible preferred stock offering in the year ended December 31, 2013, the Company, with the consent of at least 75% of the Convertible Note holders, amended the Note and Warrant Purchase Agreement under which the 2011 Notes were issued to allow for the conversion of 2011 Notes into 4,748,484 shares of Series E-4 convertible preferred stock. The outstanding principal and accrued interest of the 2011 Notes of $71.0 million were converted at a price equal to 66 2/3% of the Series E-5 offering price of $22.425 per share per the terms of the 2011 Notes. The modification of the 2011 Notes was treated as an extinguishment of debt, in which the resulting issuances of Series E-4 convertible preferred stock was recorded at its estimated fair value on the date of the extinguishment. The difference in the estimated fair value of the Series E-4 convertible preferred stock and the carrying values of the outstanding principal, accrued interest and the remaining debt issuance costs related to the 2011 Notes was recorded as a capital contribution in the amount of $32.0 million which was recognized to additional paid-in capital during the year ended December 31, 2013. The Company recognized the capital contribution as such because, immediately prior to the conversion, substantially all of the holders of the 2011 Notes were holders of the Company’s outstanding capital stock. In addition, the Company remeasured the embedded derivative to its fair value of approximately zero immediately prior to the conversion of the 2011 Notes in March 2013, as the execution of a qualified financing approached certainty, resulting in a gain of $1.8 million. As of the date of conversion, the Company was in compliance with all covenants in the 2011 Notes.
	In connection with the issuance of the 2011 Notes, the Company incurred debt issuance costs of $43,000 during the year ended December 31, 2012. These amounts were recorded as a deferred charge to be amortized to interest expense over the terms of the borrowings. The Company recognized interest expense from the amortization of the debt issuance costs of $62,000 and $145,000 during the years ended December 31, 2013 and 2012, respectively. The unamortized debt issuance costs balance was $103,000 as of December 31, 2012. There was no unamortized debt issuance cost balance or interest expense as of December 31, 2014 as the 2011 Notes were no longer outstanding.
	Also, in connection with the issuance of the 2011 Notes, the Company issued warrants to purchase 77,521 shares of common stock and with a fair value of $153,000 during the year ended December 31, 2012, with an exercise price of $0.15 per share. The relative fair value of the warrants was recorded as debt discount which was amortized to interest expense over the loan term. The Company recognized interest expense of $214,000 and $260,000 from the amortization of the warrant related debt discounts during the years ended December 31, 2013 and 2012, respectively. There was no unamortized warrant related debt discount balance as of December 31, 2014 and 2013 as the 2011 Notes were no longer outstanding.
	Also, in connection with the 2011 Notes, the Company determined that the conversion and redemption features were embedded derivatives requiring bifurcation and separate accounting. The fair value of the derivative liabilities associated with the 2011 Notes at the time of issuance was recognized as an additional debt discount and was amortized to interest expense over the term of the 2011 Notes. The Company recognized interest expense of $2.8 million and $7.1 million from the amortization of the derivative liability related debt discounts during the years ended December 31, 2013 and 2012, respectively. In the year ended December 31, 2013, the 2011 Notes converted into shares of Series E-4 convertible preferred stock. Immediately prior to the conversion, the Company determined that the fair value of the derivative liabilities associated with the convertible notes were reduced to zero. There was no unamortized derivative related debt discount balances as of December 31, 2014 and 2013 as the 2011 Notes were no longer outstanding.
	2013 Convertible Notes, Common Stock Warrants, and Related Derivatives
	In October 2013, the Company entered into a convertible promissory note and warrant agreement, referred to as the 2013 Notes, to borrow up to $30.0 million. The Company borrowed $19.4 million in the fourth quarter of 2013. In January 2014, the Company issued an additional $4.3 million in 2013 Notes. The 2013 Notes bear interest at 12% per annum and mature in October 2014. In February 2014, in connection with the Company’s IPO, the 2013 Notes with a principal amount, accrued interest through the date of the IPO, remaining interest due through October 7, 2014, and derivative liability totaling $26.2 million converted into 1,637,846 shares of the Company’s common stock.
	In connection with the issuance of the 2013 Notes, the Company issued warrants to purchase 409,450 shares of common stock. As of December 31, 2013, the fair value of these warrants of $2.7 million was classified as a liability and recorded as a debt discount that will be amortized to interest expense using the straight-line method over the loan term. The Company recognized interest expense of $1.3 million for the amortization of the warrant and embedded derivative related debt discount for the year ended December 31, 2013. In February 2014, in connection with the Company’s IPO, these warrants were net exercised for 405,594 shares of common stock.
	Additionally, the 2013 Notes had conversion and redemption features which were determined to be embedded derivatives, requiring bifurcation and separate fair value accounting. Accordingly, the Company recorded an embedded derivative liability of $5.8 million associated with the 2013 Notes on the date of issuance. The fair value of these derivative instruments was recognized as an additional discount and as a derivative liability on the consolidated balance sheets upon issuance of the respective convertible notes. The derivative liability required periodic remeasurements to fair value while the derivative was still outstanding and accordingly, the Company recognized remeasurement gains for the 2013 Notes during the years ended December 31, 2014 and 2013 of $4.0 million and $0.9 million, respectively. Immediately prior to the conversion, the Company determined that the fair value of the derivative liabilities associated with the convertible notes was reduced to $1.9 million, the value of interest due to note holders from the date of the IPO through the maturity date of the loan in October 2014.
	Prior to conversion, the fair value of the derivative liabilities associated with convertible notes was determined upon issuance and at December 31, 2013 using “Monte Carlo” simulation with the following weighted-average assumptions:
		As of December 31, 2013		As of Issuance
	Expected term (in years)	0.8		0.9
	Discount rate	16.5	%	15	%
	Weighted-average scenario probabilities:
	Maturity	5	%	5	%
	Qualified financing	5	%	20	%
	Initial public offering	80	%	60	%
	Change in control	10	%	15	%
	Upon the conversion of the 2013 Notes into shares of common stock, the Company applied extinguishment accounting resulting in a loss of $8.3 million. As of the date of conversion, the Company was in compliance with all covenants in the 2013 Notes.
	During the year ended December 31, 2014, the Company recognized non-cash interest expense of $9.6 million related to the 2013 Notes, including amortization of warrant-related debt discount of approximately $0.4 million up to the date of conversion, amortization of the derivative-related debt discount of $0.6 million up to the date of conversion, accrued interest of $0.3 million up to the date of conversion and a loss on extinguishment of $8.3 million upon conversion of the 2013 Notes into common stock. The unamortized debt discount balance was $7.2 million as of December 31, 2013.

Interest_Expense

Interest Expense	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Interest Expense	Interest Expense
	Interest expense, includes cash and non-cash components with the non-cash components consisting of (i) interest recognized from the amortization of debt issuance costs, which were capitalized on the Condensed Consolidated Balance Sheets, that are generally derived from cash payments related to the issuance of convertible notes and notes payable, (ii) interest recognized from the amortization of debt discounts, which were capitalized on the Condensed Consolidated Balance Sheets, derived from the issuance of warrants and derivatives issued in conjunction with convertible notes and notes payable, (iii) interest recognized on the 2011 convertible notes, or 2011 Notes, which was not paid but instead converted into shares of convertible preferred stock, (iv) interest recognized on the 2013 convertible notes, or 2013 Notes, which was not paid but instead converted into shares of common stock, (v) interest capitalized for assets constructed for use in operations, (vi) interest related to the extinguishment of debt, which is classified as a gain or loss on debt extinguishments, and (vii) effective interest recognized on the financing obligation. The capitalized amounts related to the debt issuance costs and debt discounts are generally amortized to interest expense over the term of the related debt instruments.
	The interest expense by cash and non-cash components is as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Interest expense
	Cash related interest expense (1)	$	(1,182	)	$	(1,590	)	$	(2,302	)
	Non-cash interest expense
	Non-cash interest expense — debt issuance costs	(203		)	(490		)	(300		)
	Non-cash interest expense — warrant and derivative related debt discounts	(650		)	(4,128		)	(7,427		)
	Non-cash interest expense — convertible notes	(1,250		)	(9,409		)	(18,930		)
	Loss on extinguishment of 2013 Notes	(8,331		)	—			—
	Effective interest on financing obligation	(28		)	—			—
	Capitalized interest expense (2)	972			453			—
	Total non-cash interest expense	(9,490		)	(13,574		)	(26,657		)
	Total interest expense	$	(10,672	)	$	(15,164	)	$	(28,959	)
	-1	Cash related interest expense included interest payments to Hercules Notes Payable and Essex Notes.
	-2	Interest expense capitalized pursuant to Accounting Standards Codification Topic 835, Interest.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Facility Lease
	In January 2010, the Company entered into a non-cancelable facility lease that requires monthly payments through January 2022. This facility will be used for research, manufacturing, and administrative functions.
	In February 2014, the Company extended the term of the Lease by thirty-six (36) months to January 2025. As part of this agreement, the Lessor shall provide the Company with a tenant improvement allowance during 2014 in an amount not to exceed $3.0 million. Under the terms of the lease agreement, the Company will make total rent payments of $72.8 million for a period of 15 years commencing in January 2010 which was determined to be an operating lease. The payments escalate over the term of the lease with the exception of a decrease in payments at the beginning of 2022, however, the Company recognizes the expense on a straight-line basis over the life of the lease.
	Rent expense for the years ended December 31, 2014, 2013 and 2012 was $5.2 million, $4.4 million, and $4.4 million. As of December 31, 2014, the aggregate total future minimum lease payments under non-cancelable operating leases were as follows (in thousands):
	Year Ending December 31,
	2015	$	5,070
	2016	5,222
	2017	5,394
	2018	5,578
	2019 and thereafter	32,354
	Total payments	$	53,618
	Other Milestone-Based Commitments
	The Company has one remaining obligation to make a future milestone payment to List Laboratories that becomes due and payable on the achievement of a certain regulatory milestone. The Company is obligated to pay royalties to List Laboratories on future sales of botulinum toxin products.
	Purchase Commitments
	The Company has certain commitments from outstanding purchase orders primarily related to clinical trial development and other costs related to the Company’s manufacturing facility. These agreements, which total $15.1 million, are cancellable at any time with the Company required to pay all costs incurred through the cancellation date.
	Contingencies
	From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of business activities. 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. The Company is not subject to any current pending legal matters or claims that would have a material adverse effect on its financial position, results of operations or cash flows.
	Indemnification
	The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to these arrangements, the Company indemnifies, holds harmless, and agrees to reimburse the indemnified parties for losses suffered or incurred by the indemnified party, in connection with any trade secret, copyright, patent or other intellectual property infringement claim by any third party with respect to its technology. The term of these indemnification agreements is generally perpetual after the execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these agreements is not determinable because it involves claims that may be made against the Company in the future, but have not yet been made. The Company has not incurred costs to defend lawsuits or settle claims related to these indemnification agreements.
	The Company has entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers, other than liabilities arising from willful misconduct of the individual.
	No amounts associated with such indemnifications have been recorded to date.

Common_Stock

Common Stock	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Common Stock	Common Stock
	As of December 31, 2014, the Company was authorized to issue up to 95,000,000 shares of par value $0.001 per share common stock.
	As of December 31, 2014 and 2013, the Company had no shares and 3,333 shares of common stock subject to repurchase. The Company has also issued shares of common stock as a result of stock option exercises throughout its existence. Common stockholders are entitled to dividends when and if declared by the Board of Directors subject to the prior rights of the preferred stockholders. The holder of each share of common stock is entitled to one vote. The common stockholders voting as a class are entitled to elect one member to the Company’s Board of Directors. As of December 31, 2014, no dividends have been declared.
	The Company had reserved shares of common stock, on an as if converted basis, for issuance as follows:
		As of December 31,
		2014	2013
	Issuances under stock incentive plans	91,634	202,562
	Issuances upon exercise of common stock warrants	198,662	760,087
	Issuances under employee stock purchase plan	174,661	—
	Issuances under inducement plan	141,500	—
	Conversion of convertible preferred stock	—	8,689,999
	Issuances upon exercise of convertible preferred stock warrants	—	184,486
		606,457	9,837,134

Convertible_Preferred_Stock

Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2014
Temporary Equity Disclosure [Abstract]
Convertible Preferred Stock	Convertible Preferred Stock
	Upon completion of the Company’s IPO in February 2014, the shares of convertible preferred stock were converted into 8,689,999 shares of common stock at a ratio of 1:1. As of December 31, 2014, there was no preferred stock outstanding.
	As December 31, 2013, outstanding convertible preferred stock was comprised of the following (in thousands, except share and per share amounts):
		Shares	Shares	Liquidation		Liquidation
		Authorized	Issued and	Value per		Value
			Outstanding	Share
	Series E-1	5,834,206	387,241	$	22.425	$	8,684
	Series E-2	8,914,007	585,559	22.425		13,131
	Series E-3	17,710,373	1,150,341	22.425		25,797
	Series E-4	72,551,683	4,748,468	22.425		106,485
	Series E-5	40,000,000	1,818,390	33.637		61,167
		145,010,269	8,689,999			$	215,264
	During the year ended December 31, 2013, the Company raised $40.8 million through the issuance of 1,818,390 shares of Series E-5 convertible preferred stock at a price of $22.425 per share. In addition, the Company issued approximately 4.7 million shares of Series E-4 convertible preferred stock with the conversion of the outstanding principal and accrued interest of the 2011 Notes (Note 8). Also in March 2013, in conjunction with the Series E-5 preferred stock financing, the Company’s previously outstanding convertible preferred stock was exchanged for shares of Series E convertible preferred stock as follows: (i) Series A and B convertible preferred stock converted into Series E-1 convertible preferred stock on a 1-for-1 basis, (ii) Series C convertible preferred stock converted into Series E-2 convertible preferred stock on a 1-for-1 basis, and (iii) Series D convertible preferred stock converted into Series E-3 convertible preferred stock on a 1-for-2.119 basis. Upon the exchange of the prior series of convertible preferred stock into the respective Series E convertible preferred stock, all outstanding shares of Series A, B-1, B-2, C-1, C-2, C-3 and D convertible preferred stock were surrendered and canceled. The exchange of the prior shares of convertible preferred stock into the respective series of Series E convertible preferred stock was accounted for as a preferred stock extinguishment. As a result of the preferred stock extinguishment and the related conversion, the Company recognized a capital contribution of $74.9 million as a benefit to net income per share attributable to common stockholders during the year ended December 31, 2013. The $74.9 million capital contribution was calculated based on the difference between the fair value of the newly issued shares of Series E convertible preferred stock as a result of the exchange and the carrying value of the previously outstanding shares of Series A, B-1, B-2, C-1, C-2, C-3 and D convertible preferred stock. The fair value of the Series E convertible preferred stock was estimated by the Company’s Board of Directors with assistance from a third party valuation that utilized methodologies and assumptions consistent with the March 31, 2013 common stock valuation. The March 31, 2013 valuation was prepared on a minority, non-marketable interest basis. The Company’s aggregate enterprise value was determined using the income approach and a form of market approach under the probability weighted expected return method or the PWERM. Under the PWERM market-based approach, all of the shares of Company’s convertible preferred stock are assumed to convert automatically upon the closing of an initial public offering. The elimination of economic rights and preferences between each of the classes of Series E convertible preferred stock in connection with an initial public offering results in fair values that are equal across each class of shares. The Series E-1, E-2, E-3, E-4 and E-5 convertible preferred stock were valued at $15.00 per share prior to any discount for lack of marketability. Under the income approach, the value of each security is conditioned upon its respective rights and restrictions, including liquidation preference, ranking, and conversion rights, such that shares of Series E-1, E-2, E-3 and E-4 convertible preferred stock are valued less than shares of Series E-5 convertible preferred stock. The Series E-5 convertible preferred stock was valued at $33.60 per share prior to any discount for lack of marketability, while the Series E-4, E-3, E-2, and E-1 convertible preferred stock were valued at $12.60, $1.95, $1.05, and $0.75 per share prior to any discount for lack of marketability based on the change of control scenarios considered in the March 31, 2013 valuation. The resulting convertible preferred stock fair values were then weighted by estimating a 60% probability to the fair value determined under the PWERM market-based approach and a 40% probability to the fair value determined under the income approach. The outcome of this weighted-average Series E-5 convertible preferred stock value was concluded to be $22.50 per share, which reconciles to the Series E-5 convertible preferred stock issue price. The same weighting was applied to all of the other convertible preferred stock securities to derive their concluded values, all of which were below the concluded value for the Series E-5 convertible preferred stock.
	The Series E-5 preferred stock financing occurred in multiple closings during the year ended December 31, 2013. Included in the first closing in February 2013 was a $2.1 million forward purchase commitment by the purchaser to buy an additional 93,333 shares of Series E-5 convertible preferred stock. This commitment was determined to be a liability since it embodied an obligation that could have required settlement by transfer of assets if the underlying convertible preferred stock was redeemed. The fair value of the liability upon issuance was not significant and the commitment was settled during the March 2013 closings. The purchasers in the first closing, who paid a higher per share price than the purchasers in the second closing, were provided with an additional 7,911 shares of Series E-5 convertible preferred stock to bring their per share equal to the per share price paid by the purchasers in the March 2013 closings. The fair value of the additional share issuance was recognized as a deemed dividend of $177,000 during the year ended December 31, 2013. The capital contribution for the extinguishment of the prior convertible preferred stock and the deemed dividend for the additional share issuance only impact the net income per share attributable to common stockholders for the period (Note 15).
	The Company recorded the convertible preferred stock at fair value on the dates of issuance. The Company classifies the convertible preferred stock outside of stockholders’ equity (deficit) (as Mezzanine) because the shares contain liquidation features that are not solely within the Company’s control. For the year ended December 31, 2013, the Company did not adjust the carrying values of the convertible preferred stock to the deemed redemption values of such shares since a liquidation event was not probable. Subsequent adjustments to increase the carrying values to the ultimate redemption values will be made only when it becomes probable that such a liquidation event will occur.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2014
Warrants and Rights Note Disclosure [Abstract]
Warrants	Warrants
	As of December 31, 2014, the Company had no convertible preferred stock warrants outstanding.
	As of December 31, 2013, the following convertible preferred stock warrants were outstanding (in thousands, except share and per share amounts):
		Number of Shares		Exercise Price		Fair Value as of December 31, 2013
		Underlying Warrants		Per Share
	Series E-3	30,338		$	31.5	$	103
	Series E-4	88,292		14.95		574
	Series E-5	65,856		22.02		556
		184,486				$	1,233
	In March 2013 in conjunction with the Series E-5 preferred stock financing, the Company’s previously outstanding warrants to purchase convertible preferred stock were exchanged for warrants to purchase shares of Series E convertible preferred stock as follows: (i) the underlying shares of Series C-2 convertible preferred stock converted into Series E-2 convertible preferred stock on a 1-for-1 basis, (ii) the underlying shares of Series C-3 convertible preferred stock converted into Series E-2 convertible preferred stock on a 1-for-1 basis, and (iii) the underlying shares of Series D convertible preferred stock converted into either Series E-3 convertible preferred stock on a 1-for-2.119 basis, Series E-4 convertible preferred stock on a 1-for-4.465 basis or Series E-5 convertible preferred stock on a 1-for-2.977 basis. In addition, the exercise price of most of the new Series E convertible preferred stock warrants was also adjusted in accordance with the terms of the exchange agreement. Upon the exchange, the prior warrants to purchase Series C-2, C-3 and D shares of convertible preferred stock were surrendered and cancelled. The exchange of warrants was accounted for as a modification. The modification resulted in an adjustment to the fair value of the warrants of $1.2 million during the year ended December 31, 2013 which was recognized in the statements of operations as a change in the fair value of the convertible preferred stock warrant liability. In July 2013, the Series E-2 warrants expired unexercised.
	In January 2014, in connection with the Company’s issuance of notes payable to Essex Capital (Note 7), the Company issued warrants to purchase 12,345 shares of Series E-5 convertible preferred stock. As of December 31, 2013, the fair value of the Essex Capital warrants was $0.1 million, which was recorded as a discount on debt and was amortized to interest expense over the term of the loan. The Company accounted for these warrants as a liability in the financial statements because the underlying instrument into which the warrants were exercisable, Series E-5 convertible preferred stock, contain deemed liquidation provisions that are outside of the Company’s control. Upon completion of the initial public offering, the convertible preferred stock warrants converted into equity-classified warrants to purchase shares of common stock.
	In February 2014, two holders of preferred stock warrants exercised their put options to sell 22,856 warrants at an exercise price equal to the average fair value of the Company’s stock price for 5 days preceding the exercise. The Company recorded a loss on cash settlement of $1.4 million as a result of this exercise.
	Upon completion of the IPO, all outstanding warrants to purchase Series E convertible preferred stock, excluding the 22,856 warrants that were exercised, converted into 173,975 warrants to purchase common stock at prices ranging from $14.95 per share to $31.50 per share, expiring in 2018 through 2021.
	The fair value of the outstanding convertible preferred stock warrants was remeasured as of December 31, 2013 using a Black-Scholes option-pricing model with the following assumptions:
		As of December 31,
		2013
	Remaining contractual term (in years)	6.5
	Expected volatility	58.8	%
	Risk-free interest rate	2.1	%
	Expected dividend rate	0	%
	Fair Value of Common Stock and Convertible Preferred Stock. The fair value of the shares of the convertible preferred stock underlying the preferred stock warrants has historically been determined by the Board of Directors. Because there has been no public market for the Company’s convertible preferred stock, the Board of Directors has determined fair value of the convertible preferred stock at each balance sheet date by considering a number of objective and subjective factors including valuation of comparable companies, sales of convertible preferred stock to unrelated third parties, operating and financial performance, the lack of liquidity of capital stock, and general and industry specific economic outlook, amongst other factors. The fair value of the shares of common stock is based on the Company's stock price.
	Remaining Contractual Term. The Company derived the remaining contractual term based on the time from the balance sheet date until the preferred stock warrant’s expiration date.
	Expected Volatility. Since the Company was a private entity with no historical data regarding the volatility of its preferred stock, the expected volatility used is based on volatility of a group of similar entities. In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size.
	Risk-Free Interest Rate. The risk-free interest rate is based on U.S. Treasury zero-coupon issues with remaining terms similar to the remaining contractual term of the warrants.
	Expected Dividend Rate. The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future, and, therefore, used an expected dividend rate of zero in the valuation model.
	As of December 31, 2014, the Company had 198,662 warrants to purchase common stock outstanding with exercise prices ranging from $14.40 to $31.50.
	In connection with the issuance of the Series E-5 convertible preferred stock during the year ended December 31, 2013, the Company also issued to the purchasers fully vested warrants to purchase an aggregate of 545,492 shares of common stock with an exercise price of $0.15 per share and a contractual term of 7 years. The fair value was determined to be $4.7 million upon issuance. The fair value of the warrants upon issuance was determined using a Black-Scholes option-pricing model with the following assumptions: expected volatility of 57.1%, contractual term of 7 years and risk-free rate of 1.3%. The fair value of the common stock warrants was recorded to additional paid-in capital upon issuance. During the year ended December 31, 2013, warrants to purchase 52,481 shares of common stock were exercised, while the other warrants from this arrangement remained outstanding as of December 31, 2013.
	Pursuant to the 2013 Note and Warrant Purchase Agreement, dated October 8, 2013, as amended, the Company issued secured subordinated convertible promissory notes, or the 2013 notes, and warrants to purchase common stock, or the 2013 warrants, in an aggregate principal amount of $19.4 million during the fourth quarter of 2013. The fair value of the warrants of $2.7 million was classified as a liability and recorded as a discount on debt and will be amortized to interest expense over the loan term. The Company accounts for these warrants as a liability in the financial statements because the number of common stock shares issuable under the common stock warrants is not fixed until exercise. The Company recorded a loss of $0.4 million and $0.6 million due to the change in fair value of these warrants for the years ended December 31, 2014 and 2013.
	In January 2014, the Company issued warrants to purchase 72,248 shares of common stock in connection with the issuance of the most recent round of the 2013 Notes (Note 8). In February 2014, following the completion of the Company’s IPO, all outstanding common stock warrants net exercised into 1,158,443 shares of common stock. In May 2014, warrants to purchase 20,066 shares of common stock were net exercised into 10,613 shares of common stock. In December 2014, the Company issued Essex Capital 44,753 common stock warrants with an exercise price of $14.40 in connection with the First Amendment to the Loan and Lease Agreement as discussed in Note 7. The fair value was determined to be $0.4 million upon issuance. The fair value of the warrants upon issuance was determined using a Black-Scholes option-pricing model with the following assumptions: expected volatility of 53%, contractual term of 4 years and risk-free rate of 1.4%. The fair value of the common stock warrants was recorded to additional paid-in capital upon issuance.

Stock_Option_Plan

Stock Option Plan	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Plan	Stock Option Plan
	Equity Incentive Plans
	In December 2012, the Company terminated the 2002 Equity Incentive Plan, or the 2002 Plan, and the stockholders approved the 2012 Equity Incentive Plan, or the 2012 Plan. Shares underlying any outstanding stock awards or stock option grants previously awarded remain subject to the terms of the 2002 Plan. Any shares available for grant or any shares canceled or forfeited prior to vesting or exercise subsequent to the termination of the 2002 Plan become available for use under the 2012 Plan. Upon the effectiveness of the 2012 Plan, the Company ceased granting any equity awards under the 2002 Plan.
	The 2012 Plan provides for the granting of stock options to employees, consultants and advisors of the Company. Options granted under the Plan may be either incentive stock options or nonqualified stock options. Incentive stock options (ISO) may be granted only to Company employees, including officers and directors who are also employees. Nonqualified stock options (NSO) may be granted to Company employees, consultants and advisors. As of December 31, 2012, the Company has reserved 339,302 shares of common stock for issuance under the 2012 Plan. The amount reserved under the 2012 Plan was increased by the Board during the year ended December 31, 2013 so that there were 202,558 shares of common stock reserved for issuance under the 2012 Plan as of December 31, 2013. Options under the 2012 Plan may be granted for periods of up to 10 years and at prices no less than 85% of the estimated fair value of the shares on the date of grant as determined by the Board of Directors, provided, however, that (i) the exercise price of an ISO and NSO shall not be less than 100% and 85% of the estimated fair value of the shares on the date of grant, and (ii) the exercise price of an ISO and NSO granted to a greater than 10% stockholder shall not be less than 110% of the estimated fair value of the shares on the date of grant. Options granted under the 2012 Plan generally vest over 4 years at a rate of 25% upon the first anniversary of the issuance date and monthly thereafter.
	On January 22, 2014, the Company’s Board of Directors authorized the adoption of the 2014 Equity Incentive Plan, or 2014 EIP, which became effective after adoption and approval by the Company’s stockholders on January 23, 2014. Initially, the aggregate number of shares of common stock that may be issued pursuant to stock awards under the 2014 EIP will not exceed 1,000,000 shares. The number of shares of common stock reserved for issuance under the Company’s 2014 EIP will automatically increase on January 1 of each year, beginning on January 1, 2015, and continuing through and including January 1, 2024, by 4% 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 Company’s 2014 EIP is 2,000,000 shares. The 2014 EIP provides for the grant of incentive stock options, or ISOs, nonstatutory stock options, or NSOs, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance-based stock awards, and other forms of equity compensation, all of which may be granted to employees, including officers, non-employee directors and consultants of the Company and its affiliates. Additionally, the 2014 EIP provides for the grant of performance cash awards. ISOs may be granted only to employees. All other awards may be granted to employees, including officers, and to non-employee directors and consultants. Under the 2014 EIP, options may be granted with different vesting terms from time to time, but not to exceed 10 years from the date of grant. Upon the effectiveness of the 2014 Plan, the Company ceased granting any equity awards under the 2012 Plan and any cancelled or forfeited shares under the 2012 and 2002 Plan will be retired.
	2014 Inducement Plan
	On August 26, 2014, the Company’s Board of Directors authorized the adoption of the 2014 Inducement Plan, or 2014 IN, which became effective immediately. Stockholder approval of the 2014 IN was not required pursuant to Rule 5635 (c)(4) of the NASDAQ Listing Rules. The 2014 IN reserves 325,000 shares of common stock and provides for the grant of NSOs that will be used exclusively for grants to individuals that were not previously employees or directors of the Company, as an inducement material to the individual’s entry into employment with the Company. Under the 2014 IN, options may be granted with different vesting terms from time to time, but not to exceed 10 years from the date of grant.
	Under the 2014 EIP and the 2014 IN plan, restricted stock awards typically vest annually over 3 or 4 years, while options typically vest over four years, either with 25% of the total grant vesting on the first anniversary of the option grant date and 1/36th of the remaining grant vesting each month thereafter or 1/48th vesting monthly.
	The following summary of stock option and restricted stock award activity, excluding 2014 IN, for the periods presented is as follows:
		Number of		Number of			Weighted				Weighted		Aggregate
		Shares		Shares			Average				Average		Intrinsic
		Available		Underlying			Exercise				Remaining		Value
		for Grant		Outstanding			Price Per				Contractual
				Options			Share				Life (in
											Years)
													(In thousands)
	Balance as of December 31, 2011	24,281		317,551			$	3.45			—		$	—
	Options granted	(10,266	)	10,266			1.35
	Options exercised	—		(2,530	)		2.55
	Options cancelled/forfeited	18,970		(18,970	)		2.7
	Balance as of December 31, 2012	32,985		306,317			3.45
	Additional shares reserved	1,080,661		—			—
	Options granted	(992,213	)	992,213			8.8
	Options exercised	—		(4,340	)		2.55
	Options cancelled/forfeited	81,125		(81,125	)		6.42
	Balance as of December 31, 2013	202,558		1,213,065			7.65
	Additional shares reserved	1,000,000		—			—
	Options granted	(728,349	)	728,349			30.21
	Awards granted	(212,450	)	212,450			—
	Options exercised	—		(238,999	)		5.96
	Options cancelled/forfeited	14,600		(14,600	)		26.89
	Awards forfeited	4,500		(4,500	)		—
	Shares cancelled/retired under 2002/2012 plans	(189,225	)	(9,617	)		—
	Balance as of December 31, 2014	91,634		1,886,148			$	17.9			8.6		$	8,645
	Vested and expected to vest as of December 31, 2014			1,809,590			$	17.94			8.6		$	8,573
	Exercisable as of December 31, 2014			497,855			$	11.29			7.4		$	4,011
	The intrinsic values of outstanding, vested and exercisable options were determined by multiplying the number of shares by the difference in exercise price of the options and the fair value of the common stock as of December 31, 2014 of $16.94 per share.
	The total intrinsic values of options exercised as of December 31, 2014, 2013 and 2012 of $2.6 million, $0.04 million and $0 were determined by multiplying the number of shares by the difference in exercise price of the options and the fair value of the common stock as of December 31, 2014, 2013, and 2012 of $16.94, $11.40 and $6.90 per share.
	The following table summarizes the stock option activity for the 2014 IN is as follows:
		Number of		Number of			Weighted				Weighted	Aggregate
		Shares		Shares			Average				Average	Intrinsic
		Available		Underlying			Exercise				Remaining	Value
		for Grant		Outstanding			Price Per				Contractual
				Options and Awards			Share				Life (in
											Years)
												(In thousands)
	Shares reserved	325,000		—			$	—			0	$	—
	Options granted	(140,125	)	140,125			22.52
	Restricted stock awards granted	(43,375	)	43,375			—
	Outstanding as of December 31, 2014	141,500		183,500			$	22.52			9.7	$	—
	Vested and expected to vest as of December 31, 2014			140,125			$	22.52			9.7	$	—
	Exercisable as of December 31, 2014			—			$	—			0	$	—
	The following table summarizes information with respect to stock options outstanding and currently exercisable as of December 31, 2014:
		Options Outstanding				Options
	Exercise Price	Number of		Weighted-		Exercisable
		Options		Average
				Remaining
				Contractual Life
				(In Years)
	$0.45 - 6.60	141,874		4.49		138,645
	$8.70	627,345		8.36		218,165
	$8.85	3,333		8.76		971
	$9.15	195,930		8.93		42,813
	$15.45 - 22.97	184,308		9.64		14,707
$24.58 - 31.1	180,833		9.22		12,660
$32.22	479,300		9.38		69,894
$32.81 - 33.45	1,800		9.52		—
$34.00	1,200		9.5		—
$34.27	2,400		9.32		—
	1,818,323				497,855
The following table summarizes information with respect to restricted stock awards outstanding as of December 31, 2014:
	Number of		Weighted-Average Grant-Date Fair Value				Aggregate
	Awards						Intrinsic
	Available						Value
	for Grant
							(In thousands)
Outstanding as of December 31, 2013	—		$	—			$	—
Granted	255,825		$	29.47
Vested	—		—
Forfeited	(4,500	)	26.89
Outstanding as of December 31, 2014	251,325		$	29.51			$	4,257
Stock Options Granted to Employees
During the years ended December 31, 2014, 2013 and 2012, the Company granted stock options to employees to purchase shares of common stock with a weighted-average grant date fair value of $29.31, $8.23 and $1.80 per share. As of December 31, 2014, 2013 and 2012, there was total unrecognized compensation cost for outstanding stock options and restricted stock awards of $19.1 million, $3.2 million and $0.03 million to be recognized over a period of approximately 3.0 years, 3.2 years, and 1.8 years, respectively.
The fair value of the employee stock options was estimated using the Black-Scholes option-pricing model the following weighted-average assumptions:
	Year Ended December 31,
	2014		2013			2012
Expected term (in years)	6		6			5.9
Expected volatility	57.4	%	59.1	%		56.9	%
Risk-free interest rate	1.9	%	1.3	%		0.8	%
Expected dividend rate	0	%	0	%		0	%
Fair Value of Common Stock. The fair value of the shares of common stock is based on the Company's stock price. Prior to the IPO, the fair value of the shares of common stock underlying the stock options has historically been determined by the Board of Directors. Because there was no public market for the Company’s common stock, the Board of Directors has determined fair value of the common stock at the time of grant of the option by considering a number of objective and subjective factors including valuation of comparable companies, sales of convertible preferred stock to unrelated third parties, operating and financial performance, the lack of liquidity of capital stock, and general and industry specific economic outlook, amongst other factors. The fair value of the underlying common stock shall be determined by the Board of Directors until such time as the Company’s common stock is listed on an established stock exchange or national market system.
Expected Term. The expected term for employees is based on the simplified method, as the Company’s stock options have the following characteristics: (i) granted at-the-money; (ii) exercisability is conditioned upon service through the vesting date; (iii) termination of service prior to vesting results in forfeiture; (iv) limited exercise period following termination of service; and (v) options are non-transferable and non-hedgeable, or “plain vanilla” options, and the Company has limited history of exercise data. The expected term for non-employees is based on the remaining contractual term.
Expected Volatility. Since the Company was a private entity with no historical data regarding the volatility of its common stock, the expected volatility used is based on volatility of a group of similar entities. In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size. 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.
Risk-Free Interest Rate. The risk-free interest rate is based on U.S. Treasury constant maturity rates with remaining terms similar to the expected term of the options.
Expected Dividend Rate. The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future, and, therefore, used an expected dividend rate of zero in the valuation model.
Forfeitures. The Company is required to estimate forfeitures at the time of grant, and revise those estimates in subsequent periods if actual forfeitures differ from those estimates. The Company uses historical data to estimate pre-vesting option forfeitures and record stock based compensation expense only for those awards that are expected to vest. To the extent actual forfeitures differ from the estimates, the difference will be recorded as a cumulative adjustment in the period that the estimates are revised.
Stock Options Granted to Nonemployees
Stock-based compensation expense related to stock options granted to nonemployees is recognized as the stock options are earned. During the years ended December 31, 2014 and 2013, the Company granted options to purchase 13,333 shares and 76,666 shares of common stock to nonemployees with a weighted-average exercise price of $15.45 and $8.74 per share.
During the year ended December 31, 2012, the Company did not grant options to purchase shares of common stock to nonemployees; however, grants to non-employee's were made prior to 2012.
Stock-based compensation expense related to stock options granted to nonemployees is recognized as the stock options are earned. The Company believes that the fair value of the stock options is more reliably measurable than the fair value of services received. The fair value of the stock options granted is calculated at each reporting date using the Black-Scholes option pricing model with the following weighted-average assumptions:
	Year Ended December 31,
	2014		2013			2012
Expected term (in years)	7.3		9			6.8
Expected volatility	56.1	%	58.8	%		57	%
Risk-free interest rate	2.1	%	2.7	%		1.2	%
Expected dividend rate	0	%	0	%		0	%
2014 Employee Stock Purchase Plan
On January 22, 2014, the Company’s board of directors authorized the adoption of the 2014 Employee Stock Purchase Plan, or 2014 ESPP, which became effective after adoption and approval by the Company’s stockholders on January 23, 2014. The maximum number of shares of common stock that may be issued under the Company’s 2014 ESPP is initially 200,000 shares. The number of shares of common stock reserved for issuance under the Company’s 2014 ESPP will automatically increase on January 1 of each year, beginning on January 1 of the year after the closing of our IPO and ending on and including January 1, 2024, by the lesser of (i) 1% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, (ii) 300,000 shares of common stock or (iii) such lesser number of shares of common stock as determined by the Company’s board of directors. Shares subject to purchase rights granted under the Company’s 2014 ESPP that terminate without having been exercised in full will return to the 2014 ESPP reserve and will not reduce the number of shares available for issuance under the Company’s 2014 ESPP. The 2014 ESPP is intended to qualify as an “employee stock purchase plan,” or ESPP, under Section 423 of the Internal Revenue Code of 1986 with the purpose of providing employees with an opportunity to purchase the Company’s common stock through accumulated payroll deductions. For the year ended December 31, 2014, the Company recorded stock-based compensation expense of $0.5 million and issued 25,339 shares of common stock to employees under the 2014 ESPP.
The fair value of the option component of the shares purchased under the 2014 ESPP was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions:
	Year Ended December 31,
	2014
Expected term (in years)	0.5
Expected volatility	46.8	%
Risk-free interest rate	0.1	%
Expected dividend rate	—	%
Fair Value of Common Stock. The fair value of the shares of common stock is based on the Company’s stock price.
Expected Term. The expected term is based on the term of the purchase period under the 2014 ESPP.
Expected Volatility. Since the Company was a private entity with little historical data regarding the volatility of its common stock, the expected volatility used is based on volatility of a group of similar entities. In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size. 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.
Risk-Free Interest Rate. The risk-free interest rate is based on U.S. Treasury constant maturity treasury rates with remaining terms similar to the expected term.
Expected Dividend Rate. The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future, and, therefore, used an expected dividend rate of zero in the valuation model.
Total Stock-Based Compensation
Total stock-based compensation expense related to options granted to employees and nonemployees was allocated as follows (in thousands):
	Year Ended December 31,
	2014			2013				2012
Research and development	$	2,357		$	194			$	48
Sales, general and administrative	4,173			354				31
Total stock based compensation expense	$	6,530		$	548			$	79
There were no capitalized stock-based compensation costs or recognized stock-based compensation tax benefits during the years ended December 31, 2014, 2013, and 2012.

Net_Income_Loss_per_Share_Attr

Net Income (Loss) per Share Attributable to Common Stockholders	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Net Income (Loss) per Share Attributable to Common Stockholders	Net Income (Loss) per Share Attributable to Common Stockholders
	The following table sets forth the computation of the Company’s basic and diluted net income (loss) per share attributable to common stockholders for the years ended December 31, 2014, 2013, and 2012 (in thousands, except for share and per share amounts):
		Year Ended December 31,
		2014				2013			2012
	Net loss	$	(62,917	)		$	(52,448	)	$	(58,259	)
	Capital contribution on the extinguishment of prior convertible preferred stock	—				74,894			—
	Deemed dividend on the issuance of Series E-5 convertible preferred stock	—				(177		)	—
	Noncumulative dividend on Series E convertible preferred stock	—				(13,878		)	—
	Undistributed earnings allocated to preferred stockholders	—				(8,133		)	—
	Net income (loss) attributable to common stockholders, basic	(62,917		)		258			(58,259		)
	Adjustments to net income (loss) for dilutive securities					825			—
	Net income (loss) attributable to common stockholders, diluted	$	(62,917	)		$	1,083		$	(58,259	)
	Net income (loss) per share attributable to common stockholders
	Basic	$	(3.24	)		$	1.17		$	(290.48	)
	Diluted	$	(3.24	)		$	1.05		$	(290.48	)
	Weighted-average shares used in computing net income (loss) per share attributable to common stockholders:
	Basic	19,391,523				220,220			200,560
	Stock options	—				167,655			—
	Warrants to purchase common stock	—				641,275			—
	Diluted	19,391,523				1,029,150			200,560
	The following common stock equivalents were excluded from the computation of diluted net income (loss) per share for the periods presented because including them would have been antidilutive:
		As of December 31,
		2014			2013			2012
	Stock options	1,818,323			—			306,312
	Convertible preferred stock	—			8,689,999			1,741,432
	Convertible preferred stock warrants	—			184,486			82,262
	Common stock warrants	198,662			—			267,166

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	Since inception, the Company has only generated pretax losses in the United States and has not generated any pretax income or loss outside of the United States. The Company did not record a provision (benefit) for income taxes for the years ended December 31, 2014 and 2013. Significant components of the Company’s deferred tax assets as of December 31, 2014 and 2013 consist of the following (in thousands):
		Year Ended December 31,
		2014			2013
	Deferred tax assets:
	Net operating loss carryforward	$	93,260		$	78,169
	Accruals and reserves	2,458			1,854
	Stock based compensation	1,602			86
	Tax credits	2,623			5,760
	Fixed and intangible assets	1,771			2,057
	Valuation Allowance	(101,714		)	(85,488		)
	Total deferred tax assets	—			2,438
	Deferred tax liabilities:
	Debt discount	—			(2,438		)
	Total deferred tax liabilities	—			(2,438		)
	Net deferred tax assets	$	—		$	—
	Reconciliations of the statutory federal income tax (benefit) to the Company’s effective tax for the years ended December 31, 2014, 2013, and 2012are as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Tax (benefit) at statutory federal rate	$	(21,392	)	$	(17,832	)	$	(19,808	)
	State Tax (benefit) — net of federal benefit	79			849			(3,398		)
	Permanent differences	660			3,931			8,887
	Debt discount	756			2,888			—
	Research and development credits	3,137			(642		)	(197		)
	Other	537			284			51
	Change in valuation allowance	16,226			10,522			14,465
	Provision for taxes	$	3		$	—		$	—
	A valuation allowance is provided when it is more likely than not that the deferred tax assets will not be realized. The Company has established a valuation allowance to offset deferred tax assets as of December 31, 2014 and 2013 due to the uncertainty of realizing future tax benefits from its net operating loss carryforwards and other deferred tax assets. The valuation allowance for a particular tax jurisdiction shall be allocated between current and non-current deferred tax assets for that tax jurisdiction on a pro-rata basis.  Accordingly, the Company has allocated the valuation allowance on a pro-rata basis between current and non-current deferred tax assets. The valuation allowance increased by $16.2 million and $10.5 million during the years ended December 31, 2014 and 2013, respectively. The valuation allowance increased primarily due to an increase in the net operating loss carryforwards incurred during the taxable years.
	As of December 31, 2014, the Company had net operating loss carryforwards available to reduce future taxable income, if any, for Federal, California, and New Jersey income tax purposes of $247.1 million, $158.3 million, and $174.8 million, respectively. If not utilized, the Federal net operating loss carryforward begin expiring in 2020, the California net operating loss carryforwards began expiring in 2010, and the New Jersey state net operating loss carryforwards begin expiring in 2030. The Company recognizes excess tax benefits associated with the exercise of stock options directly to stockholders’ equity only when realized. The net operating loss related deferred tax assets do not include excess tax benefits from employee stock option exercises. As of December 31, 2014, the net operating loss reported as a deferred tax asset does not include approximately $2.1 million attributable to excess stock option deductions. The Company follows with or without method to determine when such net operating loss has been realized.
	As of December 31, 2014, the Company also had research and development credit carryforwards of $0.4 million and $4.8 million available to reduce future taxable income, if any, for Federal and California state income tax purposes, respectively. If not utilized, the Federal credit carryforwards will begin expiring in 2023 and the California credit carryforwards have no expiration date.
	In general, if the Company experiences a greater than 50 percentage point aggregate change in ownership over a 3-year period (a Section 382 ownership change), utilization of its pre-change NOL carryforwards are subject to an annual limitation under Section 382 of the Internal Revenue Code (California and New Jersey have similar laws). The annual limitation generally is determined by multiplying the value of the Company’s stock at the time of such ownership change (subject to certain adjustments) by the applicable long-term tax-exempt rate. Such limitations may result in expiration of a portion of the NOL carryforwards before utilization. The Company determined that an ownership change occurred on April 7, 2004 but that all carryforwards can be utilized prior to the expiration. The Company also determined that an ownership change occurred in February 2014. As a result of the 2014 change, approximately $1.4 million of federal net operating loss carryforwards and $4.8 million of federal research and development, or R&D, credits are expected to expire unused. As of December 31, 2014, the Company derecognized $1.4 million of federal NOLs and $4.8 million of federal R&D credits. Since the R&D credits for California carry over indefinitely, there was no change to the California R&D credits. In order for the Company to trigger another Section 382 ownership change, the Company would need to experience a greater than 50 percentage point aggregate change in ownership within a three-year period beginning in February 2014. The Company determined that a Section 382 ownership change did not occur upon the June 2014 follow-on public offering.
	The ability of the Company to use its remaining NOL carryforwards may be further limited if the Company experiences a Section 382 ownership change in connection with the IPO or as a result of future changes in its stock ownership.
	On January 1, 2009, the Company adopted the provisions of FASB’s guidance for accounting for uncertain tax positions. The guidance prescribes a comprehensive model for the recognition, measurement, presentation and disclosure in financial statements of any uncertain tax positions that have been taken or expected to be taken on a tax return. The cumulative effect of adopting this guidance did not result in an adjustment to accumulated deficit as of January 1, 2009. No liability related to uncertain tax positions is recorded in the financial statements. It is the Company’s policy to include penalties and interest expense related to income taxes as a component of other expense and interest expense as necessary.
	The unrecognized tax benefit was $1.3 million and $2.3 million at December 31, 2014 and December 31, 2013, respectively. The Company does not expect that its uncertain tax positions will materially change in the next twelve months. No liability related to uncertain tax positions is recorded on the financial statements related to uncertain tax positions. During the year ending December 31, 2014, the amount of unrecognized tax benefits decreased due to limitation of research and development credits for prior periods offset by an increase for additional research and development credits generated during the year. The reversal of the uncertain tax benefits would not impact the Company’s effective tax rate to the extent that the Company continues to maintain a full valuation allowance against its deferred tax assets.
	The unrecognized tax benefit was as follows (in thousands):
		Unrecognized tax benefits
	Balance as of December 31, 2011	$	1,912
	Additions for current tax positions	100
	Balance as of December 31, 2012	2,012
	Additions for current tax positions	276
	Balance as of December 31, 2013	2,288
	Decrease for prior tax positions	(1,216		)
	Additions for current tax positions	196
	Balance as of December 31, 2014	$	1,268
	The Company does not expect that its uncertain tax positions will materially change in the next twelve months.
	The Company files income tax returns in the United States, California, and in New Jersey. The Company is not currently under examination by income tax authorities in federal, state or other jurisdictions. All tax returns will remain open for examination by the federal and state authorities for three and four years, respectively, from the date of utilization of any net operating loss or tax credits.

Defined_Contribution_Plan

Defined Contribution Plan	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Defined Contribution Plan	Defined Contribution Plan
	The Company sponsors a defined contribution plan under Section 401(k) of the Internal Revenue Code covering substantially all employees over the age of 21 years. Contributions made by the Company are voluntary and are determined annually by the Board of Directors on an individual basis subject to the maximum allowable amount under federal tax regulations. The Company has made no contributions to the plan since its inception.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	On January 28, 2015, the Company granted 423,788 stock options and 74,786 restricted stock awards under the 2014 EIP to executive employees. The aggregate grant date fair value is estimated to be $4.7 million. On January 30, 2015, the Company granted 79,450 stock options and 65,300 restricted stock awards under the 2014 EIP to employees. The aggregate grant date fair value is estimated to be $1.7 million.
	In February 2015, the Company executed the Second Amendment to the Loan and Lease Agreement to extend the term of the facility to no later than April 15, 2015 and increase the purchase price of the IMA Life equipment by $0.1 million to approximately $9.8 million. Concurrently with this sale, the Company will lease the IMA Life equipment from Essex Capital for a fixed monthly payment to be paid monthly over 3 years. At the end of the lease, the Company will have the option to purchase the leased equipment for 10% of the original purchase amount.
	On February 26, 2015, the Board of Directors of the Company elected Philip J. Vickers, Ph.D. to serve as a member of the Board for the term expiring at the Company’s 2015 Annual Meeting of Stockholders and until his successor is duly elected and qualified, or until his earlier death, resignation or removal. On February 26, 2015, Dr. Vickers was also granted an option to purchase 18,000 shares of common stock under the 2014 EIP with an exercise price equal to $16.46 and an estimated aggregate grant date fair value of $0.1 million. The option will vest on the one year anniversary of the date of grant, subject to Dr. Vickers’ continued service as a director through the vesting date.
	On March 4, 2015, the Company entered into an at the market issuance Sales Agreement with Cowen and Company, LLC under which the Company may offer and sell, from time to time and at its sole discretion, shares of its common stock having an aggregate offering price of up to $50 million.  The Company will pay Cowen a commission of up to 3.0% of the gross sales proceeds of any common stock sold through Cowen under the Sales Agreement. The Company has also provided Cowen with customary indemnification rights.

Quarterly_Results_of_Operation

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Data [Abstract]
Quarterly Results of Operations (Unaudited)	Quarterly Results of Operations (Unaudited)
	The following amounts are in thousands, except per share amounts:
		For the Quarters Ended
		March 31,			June 30,			September 30,			December 31,
		2014
	Revenue	$	158		$	75		$	75		$	75
	Net loss	$	(21,426	)	$	(13,302	)	$	(13,977	)	$	(14,212	)
	Net income (loss) attributable to common stockholders:
	Basic	$	(21,426	)	$	(13,302	)	$	(13,977	)	$	(14,212	)
	Diluted	$	(21,426	)	$	(13,302	)	$	(13,977	)	$	(14,212	)
	Net income (loss) per share attributable to common stockholders:
	Basic	$	(1.93	)	$	(0.69	)	$	(0.60	)	$	(0.60	)
	Diluted	$	(1.93	)	$	(0.69	)	$	(0.60	)	$	(0.60	)
		2013
	Revenue	$	75		$	75		$	158		$	309
	Net loss	$	(21,657	)	$	(11,829	)	$	(8,879	)	$	(10,083	)
	Net income (loss) attributable to common stockholders:
	Basic	$	5,216		$	(15,750	)	$	(12,789	)	$	(13,987	)
	Diluted	$	13,307		$	(15,750	)	$	(12,789	)	$	(13,987	)
	Net income (loss) per share attributable to common stockholders:
	Basic	$	25.54		$	(75.25	)	$	(55.90	)	$	(53.63	)
	Diluted	$	21		$	(75.25	)	$	(55.90	)	$	(47.11	)

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The consolidated financial statements of the Company include the Company’s accounts and those of its wholly-owned subsidiary, Revance Therapeutics Limited, and have been prepared in conformity with accounting principles generally accepted in the United States of America, or US GAAP. All significant intercompany transactions and balances have been eliminated during consolidation.
Use of Estimates	Use of Estimates
	The preparation of consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Such management estimates include the fair value of common stock, stock-based compensation, fair value of convertible preferred stock and warrants, fair value of derivatives, and the valuation of deferred tax assets. The Company bases its estimates on historical experience and also on assumptions that it believes are reasonable, however, actual results could significantly differ from those estimates.
Risks and Uncertainties	Risks and Uncertainties
	The product candidates developed by the Company require approvals from the U.S. Food and Drug Administration (FDA) or foreign regulatory agencies prior to commercial sales. There can be no assurance that the Company’s current and future product candidates will meet desired efficacy and safety requirements to obtain the necessary approvals. If the Company is denied approval or approval is delayed, it may have a material adverse impact on the Company’s business and its consolidated financial statements.
	The Company is subject to risks common to companies in the development stage including, but not limited to, dependency on the clinical and commercial success of its product candidates, ability to obtain regulatory approval of its product candidates, the need for substantial additional financing to achieve its goals, uncertainty of board adoption of its approved products, if any, by physicians and consumers, significant competition and untested manufacturing capabilities.
Concentration of Credit Risk	Concentration of Credit Risk
	Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents. Under the Company's Investment Policy, the Company limits its credit exposure by investing in highly liquid funds with high credit quality. The Company’s cash and cash equivalents are held in the United States of America. Such deposits may, at times, exceed federally insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents.
Cash and Cash Equivalents	Cash and Cash Equivalents
	The Company considers all highly liquid investment securities with remaining maturities at the date of purchase of three months or less to be cash equivalents. Cash and cash equivalents include deposit and money market funds.
Restricted Cash	Restricted Cash
	Deposits of $510,000 and $585,000 were restricted from withdrawal as of December 31, 2014 and 2013. The restriction is related to securing the Company’s facility lease and expires in 2025 in accordance with the operating lease agreement, as amended. The restrictions on these balances are being released at a rate of $75,000 per year until the balance is $400,000 and then remain at that limit until the end of the lease. These balances are included in restricted cash on the accompanying consolidated balance sheets.
Fair Value of Financial Instruments	Fair Value of Financial Instruments
	The Company uses fair value measurements to record fair value adjustments to certain financial and non-financial assets and liabilities to determine fair value disclosures. The accounting standards define fair value, establish a framework for measuring fair value, and require disclosures about fair value measurements. Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required to be recorded at fair value, the principal or most advantageous market in which the Company would transact are considered along with assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance. The accounting standard for fair value establishes a fair value hierarchy based on three levels of inputs, the first two of which are considered observable and the last unobservable, that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement.
	The three levels of inputs that may be used to measure fair value are as follows:
		Level 1	—	Observable inputs, such as quoted prices in active markets for identical assets or liabilities.
		Level 2	—	Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
		Level 3	—	Valuations based on unobservable inputs to the valuation methodology and including data about assumptions market participants would use in pricing the asset or liability based on the best information available under the circumstances.
Property and Equipment, Net	Property and Equipment, Net
	Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Computer equipment and lab equipment is depreciated over 3 and 5 years, respectively. Prior to 2014, furniture and fixtures were depreciated over 7 years, however, the Company revised its estimate to 5 years for all assets in this category beginning in 2014. Additionally, prior to 2014, manufacturing equipment was depreciation over 5 years, however, the Company revised its estimate to 7 years for all assets in this category beginning in 2014. Repairs and maintenance that do not extend the life or improve an asset are expensed in the period incurred.
	Leasehold improvements are amortized over the lesser of 15 years or the term of the lease. Repairs and maintenance are charged to operations as incurred. When assets are retired or otherwise disposed of, the costs and accumulated depreciation are removed from the consolidated balance sheets and any resulting gain or loss is reflected in the consolidated statements of operations and comprehensive loss in the period realized.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
	The Company evaluates its long-lived assets for indications of possible impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amounts to the future undiscounted cash flows, attributable to these assets. Should impairment exist, the impairment would be measured by the amount by which the carrying amount of the assets exceeds the projected discounted future cash flows arising from those assets.
Clinical Trial Accruals	Clinical Trial Accruals
	Clinical trial costs are charged to research and development expense as incurred. The Company accrues for expenses resulting from obligations under contracts with clinical research organizations (CROs) and consultants, and under clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company’s objective is to reflect the appropriate expense in the consolidated financial statements by matching the appropriate expenses with the period in which services and efforts are expended. In the event advance payments are made to a CRO, the payments will be recorded as a prepaid asset which will be amortized in accordance with the contractual terms. In addition to pass-through costs, the Company incurs costs in clinical trials in three distinct phases as follows:
	(i)	Start-up Phase — This phase includes the initial set-up of the clinical trial and usually occurs within a few months after the contract has been executed and includes costs which are expensed ratably over the start-up phase. Start-up phase activities include study initiation, site recruitment, regulatory applications, investigator meetings, screening, preparation, pre-study visits and training.
	(ii)	Site and Study Management Phase — This phase includes medical and safety monitoring, and patient administration and data management. These costs are usually calculated on a per patient basis and expensed ratably over the treatment period beginning on the date that the patient enrolls.
	(iii)	Close Down and Reporting Phase — This phase includes analyzing the data obtained and reporting results, which occurs after patients have ceased treatment and the database of information collected is locked. These costs are expensed ratably over the close down and reporting phase.
	The CRO contracts generally include pass-through fees including, but not limited to, regulatory expenses, investigator fees, travel costs and other miscellaneous costs, including shipping and printing fees. The Company determines accrual estimates through reports from and discussion with clinical personnel and outside services providers as to the progress or state of completion of trials, or the services completed. The Company estimates accrued expenses as of each balance sheet date in the consolidated financial statements based on the facts and circumstances known to the Company at that time. The Company’s clinical trial accrual is dependent, in part, upon the receipt of timely and accurate reporting from the CROs and other third party vendors.
Revenue	Revenue
	The Company recognizes revenue when the following criteria are met: persuasive evidence of a sales arrangement exists; delivery has occurred; the price is fixed or determinable; and collectability is reasonably assured.
	In August 2011, the Company entered into an asset purchase and royalty agreement for the sale of the Relastin product line for $0.05 million and royalties on future sales of Relastin. Accordingly, under the Relastin asset purchase agreement, the Company recognized royalty revenue of $0.3 million during each of the years ended December 31, 2014, 2013, and 2012 and $0.2 million in milestone revenue in the year ended December 31, 2013 for achievement of a one-time milestone.
	License revenue during the years ended December 31, 2014, 2013, and 2012 resulted from a nonrefundable technology license fee which was deferred and recognized over the estimated period of performance. The Company estimated the performance period as the remaining life of the underlying patent at the inception of the license agreement, which was periodically reevaluated. License revenue for the year ended December 31, 2014 resulted from a nonrefundable technology access fee pursuant to an exclusive technology evaluation agreement. The Company received an upfront payment of $0.3 million, which was deferred and recognized over the estimated performance period.
Research and Development Expenditures	Research and Development Expenditures
	Research and development costs are charged to operations as incurred. Research and development costs include, but are not limited to, payroll and personnel expenses, clinical trial supplies, fees for clinical trial services, consulting costs and allocated overhead, including rent, equipment, depreciation and utilities. Research and development costs during the year ended December 31, 2012 also included the fair value of technology rights returned to the Company as a result of the Medicis settlement (Note 4).
Income Taxes	Income Taxes
	The Company accounts for income taxes under the asset and liability method. The Company estimates actual current tax exposure together with assessing temporary differences resulting from differences in accounting for reporting purposes and tax purposes for certain items, such as accruals and allowances not currently deductible for tax purposes. These temporary differences result in deferred tax assets and liabilities, which are included in the Company’s consolidated balance sheets. In general, deferred tax assets represent future tax benefits to be received when certain expenses previously recognized in the Company’s consolidated statements of operations and comprehensive loss become deductible expenses under applicable income tax laws or when net operating loss or credit carryforwards are utilized. Accordingly, realization of the Company’s deferred tax assets is dependent on future taxable income against which these deductions, losses and credits can be utilized.
	The Company must assess the likelihood that the Company’s deferred tax assets will be recovered from future taxable income, and to the extent the Company believes that recovery is not likely, the Company establishes a valuation allowance. Based on the available evidence, the Company is unable, at this time, to support the determination that it is more likely than not that its deferred tax assets will be utilized in the future. Accordingly, the Company recorded a full valuation allowance as of December 31, 2014 and 2013. The Company intends to maintain valuation allowances until sufficient evidence exists to support its reversal.
Stock-Based Compensation	Stock-Based Compensation
	The Company has equity incentive plans under which various types of equity-based awards, including incentive stock options, nonqualified stock options, and restricted stock awards, may be granted to employees and nonemployee consultants. The Company also has an inducement plan under which various types of equity-based awards, including nonqualified stock options and restricted stock awards, may be granted to new employees.
	For stock options granted to employees, the Company recognizes compensation expense for all stock-based awards based on the grant-date estimated fair values, net of an estimated forfeiture rate. For restricted stock awards to employees, the fair value is based on the closing price of the Company's common stock on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as expense ratably over the requisite service period. The fair value of stock options is determined using the Black-Scholes option pricing model. The Company estimates its forfeiture rate based on an analysis of its actual forfeitures and will continue to evaluate the adequacy of the forfeiture rate assumption based on actual forfeitures, analysis of employee turnover, and other related factors.
	Stock-based compensation expense related to stock options granted to nonemployees is recognized based on the fair value of the stock options, determined using the Black-Scholes option pricing model, as they are earned. The awards vest over the time period the Company expects to receive services from the nonemployee.
Warrants	Warrants
	The Company has issued freestanding warrants to purchase shares of common stock and convertible preferred stock in connection with certain debt and lease transactions. The warrants are recorded at fair value using the Black-Scholes option pricing model.
Common Stock Warrants	Common Stock Warrants
	Prior to completion of the IPO, the Company accounted for warrants to purchase shares of its common stock in connection with the 2013 Notes as liabilities at fair value because these warrants may have obligated the Company to transfer assets to the holders at a future date under certain circumstances, such as change of control. The Company remeasured these warrants to current fair value at each balance sheet date, with changes in fair value recognized as a change in fair value of the warrant liability on the consolidated statements of operations and comprehensive loss. Upon completion of the IPO, these warrant liabilities were remeasured to fair value and settled in conjunction with a cashless net exercise of these warrants. Common stock warrants classified as equity at inception are recorded to additional paid-in capital at fair value upon issuance.
Convertible Preferred Stock Warrants	Convertible Preferred Stock Warrants
	The Company accounted for previously outstanding warrants to purchase shares of its convertible preferred stock that are contingently redeemable as liabilities at their estimated fair value because these warrants obligated the Company to transfer assets to the holders at a future date under certain circumstances, such as a deemed liquidation event. The warrants were subject to remeasurement to fair value at each balance sheet date, with changes in fair value recognized as change in fair value of convertible preferred stock warrant liability on the consolidated statements of operations and comprehensive loss. Upon completion of the IPO, the convertible preferred stock warrants converted into equity-classified warrants to purchase shares of common stock.
Derivative Liabilities	Derivative Liabilities
	The Company bifurcated and separately accounted for derivative instruments related to redemption and conversion features embedded within previously outstanding convertible notes and other derivative instruments related to payment provisions underlying the Medicis settlement. These derivatives are accounted for as liabilities, which will be remeasured to fair value as of each balance sheet date, with changes in fair value recognized in the Consolidated Statements of Operations and Comprehensive Loss. The derivative liabilities associated with the 2013 Convertible Notes are no longer outstanding due to the conversion of the related convertible notes upon the IPO in February 2014. The Company will continue to record adjustments to the fair value of the derivative liabilities associated with the Medicis settlement until the related settlement payments have been paid.
Comprehensive Loss	Comprehensive Loss
	Comprehensive loss is defined as a change in equity of a business enterprise during a period, resulting from transactions from non-owner sources. There have been no material items qualifying as other comprehensive loss and, therefore, for all periods presented, the Company’s comprehensive loss was the same as its reported net loss.
Net Income (Loss) per Share Attributable to Common Stockholders	Net Income (Loss) per Share Attributable to Common Stockholders
	The Company calculates its basic and diluted net income (loss) per share attributable to common stockholders in conformity with the two-class method required for companies with participating securities. Under the two-class method, the Company determines whether it has net income attributable to common stockholders, which includes the results of operations, capital contributions and deemed dividends less current period convertible preferred stock non-cumulative dividends. If it is determined that the Company does have net income attributable to common stockholders during a period, the related undistributed earnings are then allocated between common stock and the convertible preferred stock based on the weighted average number of shares outstanding during the period to determine the numerator for the basic net income per share attributable to common stockholders. In computing diluted net income attributable to common stockholders, undistributed earnings are re-allocated to reflect the potential impact of dilutive securities to determine the numerator for the diluted net income per share attributable to common stockholders. The Company’s basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) by the weighted average number of shares of common stock outstanding for the period. The diluted net income (loss) per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. The diluted net income (loss) per share attributable to common stockholders also includes vested restricted stock awards and, if the effect is not anti-dilutive, unvested restricted stock awards. For purposes of this calculation, options to purchase common stock, restricted stock, and common stock warrants are considered common stock equivalents.
Interest Expense	Interest Expense
	Interest expense, includes cash and non-cash components with the non-cash components consisting of (i) interest recognized from the amortization of debt issuance costs, which were capitalized on the Consolidated Balance Sheets, that are generally derived from cash payments related to the issuance of convertible notes and notes payable, (ii) interest recognized from the amortization of debt discounts, which were capitalized on the Consolidated Balance Sheets, derived from the issuance of warrants and derivatives issued in conjunction with convertible notes and notes payable, (iii) interest recognized on the 2011 convertible notes, or 2011 Notes, which was not paid but instead converted into shares of convertible preferred stock, (iv) interest recognized on the 2013 convertible notes, or 2013 Notes, which was not paid but instead converted into shares of common stock, (v) interest capitalized for assets constructed for use in operations, (vi) interest related to the extinguishment of debt, which is classified as a gain or loss on debt extinguishments, and (vii) effective interest recognized on the financing obligation. The capitalized amounts related to the debt issuance costs and debt discounts are generally amortized to interest expense over the term of the related debt instruments.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In August 2014, the FASB issued Accounting Standard Update No. 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40), which will require management to assess an entity’s ability to continue as a going concern at each annual and interim period. Related footnote disclosures will be required if conditions give rise to substantial doubt about an entity’s ability to continue as a going concern within one year of the report issuance date. If conditions do not give rise to substantial doubt, no disclosures will be required specific to going concern uncertainties. The guidance defines substantial doubt using a likelihood threshold of “probable” similar to the current use of that term in U.S. GAAP for loss contingencies and provides example indicators. The guidance is effective for reporting periods ending after December 15, 2016, and early adoption is permitted. The Company is currently evaluating the impact of the adoption of this guidance on the Company’s financial statements.
	In June 2014, the FASB issued Accounting Standard Update No. 2014-10, Development Stage Entities (Topic 915): Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation, which removes the distinction between development stage entities and other reporting entities, eliminates the exception provided to development stage entities for determining whether an entity is a variable interest entity on the basis of the amount of investment equity that is at risk, and clarifies disclosure requirements related to risks and uncertainties. The changes eliminate the requirements for development stage entities to (1) present inception-to-date information on the statements of operations, cash flows, and stockholders’ equity, (2) label the financial statements as those of a development stage entity, (3) disclose a description of the development stage activities in which the entity is engaged, and (4) disclose in the first year in which the entity is no longer a development stage entity that the prior years it had been in the development stage. The Company evaluated the new guidance and adopted the new standard early, beginning with the quarterly period ended June 30, 2014.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Instruments	The fair value of these instruments was as follows (in thousands):
		December 31, 2014
		Fair Value			Level 1			Level 2			Level 3
	Assets
	Money market funds	$	166,038		$	166,038		$	—		$	—
	Total assets measured at fair value	$	166,038		$	166,038		$	—		$	—
	As of December 31, 2013, the Company did not hold any assets that were measured at fair value on a recurring basis.
		As of December 31, 2014
		Fair Value			Level 1			Level 2			Level 3
	Liabilities
	Derivative liabilities associated with the Medicis settlement	$	1,541		$	—		$	—		$	1,541
	Total liabilities measured at fair value	$	1,541		$	—		$	—		$	1,541
		As of December 31, 2013
		Fair Value			Level 1			Level 2			Level 3
	Liabilities
	Derivative liabilities associated with convertible notes	$	4,890		$	—		$	—		$	4,890
	Derivative liabilities associated with the Medicis settlement	8,294			—			—			8,294
	Common stock warrant liability	3,358			—			—			3,358
	Convertible preferred stock warrant liability	1,233			—			—			1,233
	Total liabilities measured at fair value	$	17,775		$	—		$	—		$	17,775
Summary of Changes in Fair Value of Financial Instruments	The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial instruments as follows (in thousands):
		Derivative			Derivative			Common			Convertible
		Liability			Liability			Stock Warrant			Preferred
		Associated with			Associated with			Liability			Stock Warrant
		Convertible			the Medicis						Liability
		Notes			Settlement
	Fair value as of December 31, 2012	$	1,800		$	15,268		$	—		$	351
	Fair value of financial instruments issued	5,750			—			2,737			139
	Payments against Medicis liabilities	—			(6,927		)	—			—
	Modification remeasurement	—			—			—			1,168
	Change in fair value	(2,660		)	(47		)	621			(425		)
	Fair value as of December 31, 2013	4,890			8,294			3,358			1,233
	Fair value of financial instruments issued	1,050			—			981			80
	Cash payments against Medicis liabilities	—			(7,073		)	—			—
	Change in fair value	(4,032		)	320			2,151			210
	Extinguishment of warrant liability upon exercise of put option by warrant holder	—			—			—			(82		)
	Balance upon conversion	(1,908		)	—			(6,490		)	(1,441		)
	Fair value as of December 31, 2014	$	—		$	1,541		$	—		$	—

Balance_Sheet_Components_Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2014
Balance Sheet Components [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consists of the following (in thousands):
		As of December 31,
		2014			2013
	Research equipment	$	10,914		$	9,045
	Computer equipment	477			496
	Furniture and fixtures	534			451
	Leasehold improvements	3,833			3,632
	Construction in progress	13,422			8,880
	Total property and equipment	29,180			22,504
	Less: accumulated depreciation and amortization	(9,906		)	(8,189		)
	Property and equipment, net	$	19,274		$	14,315
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following (in thousands):
		As of December 31,
		2014			2013
	Prepaid expenses	$	1,085		$	531
	Accounts receivable	300			225
	Other current assets	239			69
	Total prepaid expenses and other current assets	$	1,624		$	825
Schedule of Accruals and Other Current Liabilities	Accruals and other current liabilities consist of the following (in thousands):
		As of December 31,
		2014			2013
	Accrued compensation	$	2,088		$	689
	Accrued professional service fees	577			367
	Accrued manufacturing and quality control costs	361			—
	Accrued clinical trial expenses	322			169
	Accrued fixed assets	266			—
	Accrued construction-in-progress obligations	60			1,757
	Accrued interest on notes payable	23			478
	Accrued initial public offering costs	—			506
	Other current liabilities	448			195
	Total accruals and other current liabilities	$	4,145		$	4,161
Schedule of Other Non-Current Assets	Other non-current assets consist of the following (in thousands):
		As of December 31,
		2014			2013
	Deferred initial public offering costs	$	—		$	2,812
	Unamortized debt issuance costs	—			194
	Prepaid expenses, non-current	$	29		$	—
	Total other non-current assets	$	29		$	3,006

Notes_Payable_Tables

Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Summary of Future Principal Payments under the Notes Payable	As of December 31, 2014, future principal payments under the Hercules Notes Payable are as follows (in thousands):
	Year Ending December 31,
	2015	2,641
	Total principal payments	2,641
	Less: debt discount	(6		)
	Less: current portion	(2,635		)
	Long-term portion of notes payable	$	—
Summary of Aggregate Total Future Minimum Lease Payments under the Financing Obligation	As of December 31, 2014, the aggregate total future minimum lease payments under the financing obligation were as follows (in thousands):
	Year Ending December 31,
	2015	423
	2016	423
	2017	141
	Total payments	987

Convertible_Notes_Warrants_and1

Convertible Notes, Warrants, and Related Derivatives (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Fair Value Measurements, Nonrecurring	Prior to conversion, the fair value of the derivative liabilities associated with convertible notes was determined upon issuance and at December 31, 2013 using “Monte Carlo” simulation with the following weighted-average assumptions:
		As of December 31, 2013		As of Issuance
	Expected term (in years)	0.8		0.9
	Discount rate	16.5	%	15	%
	Weighted-average scenario probabilities:
	Maturity	5	%	5	%
	Qualified financing	5	%	20	%
	Initial public offering	80	%	60	%
	Change in control	10	%	15	%

Interest_Expense_Tables

Interest Expense (Tables)	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Summary of Interest Expense by Cash and Non-Cash Components	The interest expense by cash and non-cash components is as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Interest expense
	Cash related interest expense (1)	$	(1,182	)	$	(1,590	)	$	(2,302	)
	Non-cash interest expense
	Non-cash interest expense — debt issuance costs	(203		)	(490		)	(300		)
	Non-cash interest expense — warrant and derivative related debt discounts	(650		)	(4,128		)	(7,427		)
	Non-cash interest expense — convertible notes	(1,250		)	(9,409		)	(18,930		)
	Loss on extinguishment of 2013 Notes	(8,331		)	—			—
	Effective interest on financing obligation	(28		)	—			—
	Capitalized interest expense (2)	972			453			—
	Total non-cash interest expense	(9,490		)	(13,574		)	(26,657		)
	Total interest expense	$	(10,672	)	$	(15,164	)	$	(28,959	)
	-1	Cash related interest expense included interest payments to Hercules Notes Payable and Essex Notes.
	-2	Interest expense capitalized pursuant to Accounting Standards Codification Topic 835, Interest.

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases	As of December 31, 2014, the aggregate total future minimum lease payments under non-cancelable operating leases were as follows (in thousands):
	Year Ending December 31,
	2015	$	5,070
	2016	5,222
	2017	5,394
	2018	5,578
	2019 and thereafter	32,354
	Total payments	$	53,618

Common_Stock_Tables

Common Stock (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Schedule of Reserved Shares of Common Stock	The Company had reserved shares of common stock, on an as if converted basis, for issuance as follows:
		As of December 31,
		2014	2013
	Issuances under stock incentive plans	91,634	202,562
	Issuances upon exercise of common stock warrants	198,662	760,087
	Issuances under employee stock purchase plan	174,661	—
	Issuances under inducement plan	141,500	—
	Conversion of convertible preferred stock	—	8,689,999
	Issuances upon exercise of convertible preferred stock warrants	—	184,486
		606,457	9,837,134

Convertible_Preferred_Stock_Ta

Convertible Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2014
Temporary Equity Disclosure [Abstract]
Schedule of Outstanding Convertible Preferred Stock	As December 31, 2013, outstanding convertible preferred stock was comprised of the following (in thousands, except share and per share amounts):
		Shares	Shares	Liquidation		Liquidation
		Authorized	Issued and	Value per		Value
			Outstanding	Share
	Series E-1	5,834,206	387,241	$	22.425	$	8,684
	Series E-2	8,914,007	585,559	22.425		13,131
	Series E-3	17,710,373	1,150,341	22.425		25,797
	Series E-4	72,551,683	4,748,468	22.425		106,485
	Series E-5	40,000,000	1,818,390	33.637		61,167
		145,010,269	8,689,999			$	215,264

Warrants_Tables

Warrants (Tables)	12 Months Ended
	Dec. 31, 2014
Warrants and Rights Note Disclosure [Abstract]
Schedule of Stockholders' Equity Note, Warrants or Rights	As of December 31, 2013, the following convertible preferred stock warrants were outstanding (in thousands, except share and per share amounts):
		Number of Shares		Exercise Price		Fair Value as of December 31, 2013
		Underlying Warrants		Per Share
	Series E-3	30,338		$	31.5	$	103
	Series E-4	88,292		14.95		574
	Series E-5	65,856		22.02		556
		184,486				$	1,233
Schedule of Assumptions Used Under Black-Scholes Model	The fair value of the outstanding convertible preferred stock warrants was remeasured as of December 31, 2013 using a Black-Scholes option-pricing model with the following assumptions:
		As of December 31,
		2013
	Remaining contractual term (in years)	6.5
	Expected volatility	58.8	%
	Risk-free interest rate	2.1	%
	Expected dividend rate	0	%

Stock_Option_Plan_Tables

Stock Option Plan (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option and Restricted Stock Award Activity	The following summary of stock option and restricted stock award activity, excluding 2014 IN, for the periods presented is as follows:
		Number of		Number of			Weighted				Weighted		Aggregate
		Shares		Shares			Average				Average		Intrinsic
		Available		Underlying			Exercise				Remaining		Value
		for Grant		Outstanding			Price Per				Contractual
				Options			Share				Life (in
											Years)
													(In thousands)
	Balance as of December 31, 2011	24,281		317,551			$	3.45			—		$	—
	Options granted	(10,266	)	10,266			1.35
	Options exercised	—		(2,530	)		2.55
	Options cancelled/forfeited	18,970		(18,970	)		2.7
	Balance as of December 31, 2012	32,985		306,317			3.45
	Additional shares reserved	1,080,661		—			—
	Options granted	(992,213	)	992,213			8.8
	Options exercised	—		(4,340	)		2.55
	Options cancelled/forfeited	81,125		(81,125	)		6.42
	Balance as of December 31, 2013	202,558		1,213,065			7.65
	Additional shares reserved	1,000,000		—			—
	Options granted	(728,349	)	728,349			30.21
	Awards granted	(212,450	)	212,450			—
	Options exercised	—		(238,999	)		5.96
	Options cancelled/forfeited	14,600		(14,600	)		26.89
	Awards forfeited	4,500		(4,500	)		—
	Shares cancelled/retired under 2002/2012 plans	(189,225	)	(9,617	)		—
	Balance as of December 31, 2014	91,634		1,886,148			$	17.9			8.6		$	8,645
	Vested and expected to vest as of December 31, 2014			1,809,590			$	17.94			8.6		$	8,573
	Exercisable as of December 31, 2014			497,855			$	11.29			7.4		$	4,011
	The following table summarizes the stock option activity for the 2014 IN is as follows:
		Number of		Number of			Weighted				Weighted	Aggregate
		Shares		Shares			Average				Average	Intrinsic
		Available		Underlying			Exercise				Remaining	Value
		for Grant		Outstanding			Price Per				Contractual
				Options and Awards			Share				Life (in
											Years)
												(In thousands)
	Shares reserved	325,000		—			$	—			0	$	—
	Options granted	(140,125	)	140,125			22.52
	Restricted stock awards granted	(43,375	)	43,375			—
	Outstanding as of December 31, 2014	141,500		183,500			$	22.52			9.7	$	—
	Vested and expected to vest as of December 31, 2014			140,125			$	22.52			9.7	$	—
	Exercisable as of December 31, 2014			—			$	—			0	$	—
Schedule of Stock Options and Restricted Stock Exercise Price Range	The following table summarizes information with respect to stock options outstanding and currently exercisable as of December 31, 2014:
		Options Outstanding				Options
	Exercise Price	Number of		Weighted-		Exercisable
		Options		Average
				Remaining
				Contractual Life
				(In Years)
	$0.45 - 6.60	141,874		4.49		138,645
	$8.70	627,345		8.36		218,165
	$8.85	3,333		8.76		971
	$9.15	195,930		8.93		42,813
	$15.45 - 22.97	184,308		9.64		14,707
	$24.58 - 31.1	180,833		9.22		12,660
	$32.22	479,300		9.38		69,894
	$32.81 - 33.45	1,800		9.52		—
	$34.00	1,200		9.5		—
	$34.27	2,400		9.32		—
		1,818,323				497,855
Fair Value Assumptions	The fair value of the option component of the shares purchased under the 2014 ESPP was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions:
		Year Ended December 31,
		2014
	Expected term (in years)	0.5
	Expected volatility	46.8	%
	Risk-free interest rate	0.1	%
	Expected dividend rate	—	%
	The fair value of the employee stock options was estimated using the Black-Scholes option-pricing model the following weighted-average assumptions:
		Year Ended December 31,
		2014		2013			2012
	Expected term (in years)	6		6			5.9
	Expected volatility	57.4	%	59.1	%		56.9	%
	Risk-free interest rate	1.9	%	1.3	%		0.8	%
	Expected dividend rate	0	%	0	%		0	%
	The fair value of the stock options granted is calculated at each reporting date using the Black-Scholes option pricing model with the following weighted-average assumptions:
		Year Ended December 31,
		2014		2013			2012
	Expected term (in years)	7.3		9			6.8
	Expected volatility	56.1	%	58.8	%		57	%
	Risk-free interest rate	2.1	%	2.7	%		1.2	%
	Expected dividend rate	0	%	0	%		0	%
Schedule of Stock-based Compensation Expense	Total stock-based compensation expense related to options granted to employees and nonemployees was allocated as follows (in thousands):
		Year Ended December 31,
		2014			2013				2012
	Research and development	$	2,357		$	194			$	48
	Sales, general and administrative	4,173			354				31
	Total stock based compensation expense	$	6,530		$	548			$	79
Nonvested Restricted Stock Shares Activity	The following table summarizes information with respect to restricted stock awards outstanding as of December 31, 2014:
		Number of		Weighted-Average Grant-Date Fair Value				Aggregate
		Awards						Intrinsic
		Available						Value
		for Grant
								(In thousands)
	Outstanding as of December 31, 2013	—		$	—			$	—
	Granted	255,825		$	29.47
	Vested	—		—
	Forfeited	(4,500	)	26.89
	Outstanding as of December 31, 2014	251,325		$	29.51			$	4,257

Net_Income_Loss_per_Share_Attr1

Net Income (Loss) per Share Attributable to Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders	The following table sets forth the computation of the Company’s basic and diluted net income (loss) per share attributable to common stockholders for the years ended December 31, 2014, 2013, and 2012 (in thousands, except for share and per share amounts):
		Year Ended December 31,
		2014				2013			2012
	Net loss	$	(62,917	)		$	(52,448	)	$	(58,259	)
	Capital contribution on the extinguishment of prior convertible preferred stock	—				74,894			—
	Deemed dividend on the issuance of Series E-5 convertible preferred stock	—				(177		)	—
	Noncumulative dividend on Series E convertible preferred stock	—				(13,878		)	—
	Undistributed earnings allocated to preferred stockholders	—				(8,133		)	—
	Net income (loss) attributable to common stockholders, basic	(62,917		)		258			(58,259		)
	Adjustments to net income (loss) for dilutive securities					825			—
	Net income (loss) attributable to common stockholders, diluted	$	(62,917	)		$	1,083		$	(58,259	)
	Net income (loss) per share attributable to common stockholders
	Basic	$	(3.24	)		$	1.17		$	(290.48	)
	Diluted	$	(3.24	)		$	1.05		$	(290.48	)
	Weighted-average shares used in computing net income (loss) per share attributable to common stockholders:
	Basic	19,391,523				220,220			200,560
	Stock options	—				167,655			—
	Warrants to purchase common stock	—				641,275			—
	Diluted	19,391,523				1,029,150			200,560
Summary of Common Stock Equivalents Excluded from Computation of Diluted Net Income (Loss) Per Share	The following common stock equivalents were excluded from the computation of diluted net income (loss) per share for the periods presented because including them would have been antidilutive:
		As of December 31,
		2014			2013			2012
	Stock options	1,818,323			—			306,312
	Convertible preferred stock	—			8,689,999			1,741,432
	Convertible preferred stock warrants	—			184,486			82,262
	Common stock warrants	198,662			—			267,166

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Significant Components of Deferred Tax Assets	Significant components of the Company’s deferred tax assets as of December 31, 2014 and 2013 consist of the following (in thousands):
		Year Ended December 31,
		2014			2013
	Deferred tax assets:
	Net operating loss carryforward	$	93,260		$	78,169
	Accruals and reserves	2,458			1,854
	Stock based compensation	1,602			86
	Tax credits	2,623			5,760
	Fixed and intangible assets	1,771			2,057
	Valuation Allowance	(101,714		)	(85,488		)
	Total deferred tax assets	—			2,438
	Deferred tax liabilities:
	Debt discount	—			(2,438		)
	Total deferred tax liabilities	—			(2,438		)
	Net deferred tax assets	$	—		$	—
Reconciliations of Statutory Federal Income Tax to Effective Tax Rate	Reconciliations of the statutory federal income tax (benefit) to the Company’s effective tax for the years ended December 31, 2014, 2013, and 2012are as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Tax (benefit) at statutory federal rate	$	(21,392	)	$	(17,832	)	$	(19,808	)
	State Tax (benefit) — net of federal benefit	79			849			(3,398		)
	Permanent differences	660			3,931			8,887
	Debt discount	756			2,888			—
	Research and development credits	3,137			(642		)	(197		)
	Other	537			284			51
	Change in valuation allowance	16,226			10,522			14,465
	Provision for taxes	$	3		$	—		$	—
Unrecognized Tax Benefit	The unrecognized tax benefit was as follows (in thousands):
		Unrecognized tax benefits
	Balance as of December 31, 2011	$	1,912
	Additions for current tax positions	100
	Balance as of December 31, 2012	2,012
	Additions for current tax positions	276
	Balance as of December 31, 2013	2,288
	Decrease for prior tax positions	(1,216		)
	Additions for current tax positions	196
	Balance as of December 31, 2014	$	1,268

Quarterly_Results_of_Operation1

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Data [Abstract]
Schedule of Quarterly Financial Information	The following amounts are in thousands, except per share amounts:
		For the Quarters Ended
		March 31,			June 30,			September 30,			December 31,
		2014
	Revenue	$	158		$	75		$	75		$	75
	Net loss	$	(21,426	)	$	(13,302	)	$	(13,977	)	$	(14,212	)
	Net income (loss) attributable to common stockholders:
	Basic	$	(21,426	)	$	(13,302	)	$	(13,977	)	$	(14,212	)
	Diluted	$	(21,426	)	$	(13,302	)	$	(13,977	)	$	(14,212	)
	Net income (loss) per share attributable to common stockholders:
	Basic	$	(1.93	)	$	(0.69	)	$	(0.60	)	$	(0.60	)
	Diluted	$	(1.93	)	$	(0.69	)	$	(0.60	)	$	(0.60	)
		2013
	Revenue	$	75		$	75		$	158		$	309
	Net loss	$	(21,657	)	$	(11,829	)	$	(8,879	)	$	(10,083	)
	Net income (loss) attributable to common stockholders:
	Basic	$	5,216		$	(15,750	)	$	(12,789	)	$	(13,987	)
	Diluted	$	13,307		$	(15,750	)	$	(12,789	)	$	(13,987	)
	Net income (loss) per share attributable to common stockholders:
	Basic	$	25.54		$	(75.25	)	$	(55.90	)	$	(53.63	)
	Diluted	$	21		$	(75.25	)	$	(55.90	)	$	(47.11	)

The_Company_and_Basis_of_Prese1

The Company and Basis of Presentation - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended								12 Months Ended			1 Months Ended
	Jan. 31, 2014	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2014	Jun. 30, 2014	Dec. 31, 2011
Subsidiary, Sale of Stock [Line Items]
Company's incorporation date										10-Aug-99
Commencement date of operations										30-Jun-02
Change of entity name date										19-Apr-05
Net loss		$14,212,000	$13,977,000	$13,302,000	$21,426,000	$10,083,000	$8,879,000	$11,829,000	$21,657,000	$62,917,000	$52,448,000	$58,259,000
Working capital surplus		162,500,000								162,500,000
Accumulated deficit		-258,797,000				-195,880,000				-258,797,000	-195,880,000
Cash and cash equivalents		171,032,000				3,914,000				171,032,000	3,914,000	4,083,000			29,621,000
Cash and cash equivalents, expected funding term for operating plan										12 months
Proceeds from issuance of common stock, net of deferred follow-on public offering costs										131,880,000	0	0
Reverse stock split, conversion ratio	0.0667
IPO
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)													6,900,000
Offering price per share (in dollars per share)													$16
Exercise of the underwriters' over-allotment option (in shares)													900,000
Proceeds from issuance of common stock, net of deferred follow-on public offering costs													98,600,000
Follow On Offering
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares)														4,600,000
Offering price per share (in dollars per share)				$30.50										$30.50
Exercise of the underwriters' over-allotment option (in shares)														600,000
Proceeds from issuance of common stock, net of deferred follow-on public offering costs														$131,300,000

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 31, 2011
Accounting Policies [Abstract]
Restricted cash	$510,000	$585,000
Annual release of restricted cash	75,000
Restricted cash, balance to remain until end of lease	400,000
Impairment	0	0	0
Property, Plant and Equipment [Line Items]
Royalty revenue	300,000	300,000	300,000
Milestone revenue		200,000
Deferred revenue	300,000
Relastin [Member]
Property, Plant and Equipment [Line Items]
Asset purchase and royalty agreement, sale price				$50,000
Computer equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Lab equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years	7 years
Manufacturing equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years

License_Agreements_Details

License Agreements (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013	Jul. 31, 2009
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue	$300,000
Research and development costs expensed	33,390,000	27,831,000	32,708,000
Procter and Gamble | Collaborative Arrangement, Product
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
License revenue	100,000	200,000	400,000
Deferred revenue				300,000
Medicis, Subsequently Acquired by Valeant Pharmaceuticals International, Inc. | Collaborative Arrangement, Product
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue					10,000,000
List Biological Laboratories, Inc. | Collaborative Arrangement, Product
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development costs expensed	$0	$0	$2,000,000

Medicis_Settlement_Additional_

Medicis Settlement - Additional Information (Detail) (USD $)	12 Months Ended		1 Months Ended	0 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Oct. 31, 2012	Feb. 13, 2014
Settlement And Termination [Line Items]
Fair value of derivative				$7.10
Gain (loss) on derivative liability due to remeasurement	-0.3	0.05
Medicis Pharmaceutical Corporation
Settlement And Termination [Line Items]
Settlement consideration payable			25
Upfront payment paid			7
Interest rate in effect on third anniversary of the Settlement Date			8.00%
Medicis Pharmaceutical Corporation | Proceeds Sharing Arrangement
Settlement And Termination [Line Items]
Settlement agreement, payable			14
Settlement payment	7.1	6.9		7.1
Fair value of derivative		6.7		7.1
Remaining contractual term (in years)	3 years 6 months	3 years 3 months
Risk-free interest rate	1.20%	0.90%
Remeasurement gain (loss)				0.3
Fair value assumptions, credit risk adjustment	6.50%	6.00%
Medicis Pharmaceutical Corporation | Product Approval Payment Derivative
Settlement And Termination [Line Items]
Settlement agreement, payable			4
Fair value of derivative	$1.50	$1.60
Medicis Pharmaceutical Corporation | Maximum | Proceeds Sharing Arrangement
Settlement And Termination [Line Items]
Remaining contractual term (in years)		6 months
Risk-free interest rate		0.10%
Fair value assumptions, expected volatility		47.50%
Medicis Pharmaceutical Corporation | Minimum | Proceeds Sharing Arrangement
Settlement And Termination [Line Items]
Remaining contractual term (in years)		1 month 2 days
Risk-free interest rate		0.01%
Fair value assumptions, expected volatility		37.00%

Fair_Value_Measurements_Schedu

Fair Value Measurements - Schedule of Fair Value of Financial Instruments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets measured at fair value	$166,038
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets measured at fair value	166,038
Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets measured at fair value	166,038
Total liabilities measured at fair value	0	0
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets measured at fair value	166,038
Level 1 | Derivative liabilities associated with the Medicis settlement
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value	0	0
Level 1 | Derivative liabilities associated with convertible notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		0
Level 1 | Common stock warrant liability
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		0
Level 1 | Convertible preferred stock warrant liability
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets measured at fair value	0
Total liabilities measured at fair value	0	0
Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets measured at fair value	0
Level 2 | Derivative liabilities associated with the Medicis settlement
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value	0	0
Level 2 | Derivative liabilities associated with convertible notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		0
Level 2 | Common stock warrant liability
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		0
Level 2 | Convertible preferred stock warrant liability
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets measured at fair value	0
Total liabilities measured at fair value	1,541	17,775
Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total assets measured at fair value	0
Level 3 | Derivative liabilities associated with the Medicis settlement
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value	1,541	8,294
Level 3 | Derivative liabilities associated with convertible notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		4,890
Level 3 | Common stock warrant liability
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		3,358
Level 3 | Convertible preferred stock warrant liability
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		1,233
Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value	1,541	17,775
Recurring | Derivative liabilities associated with the Medicis settlement
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value	1,541	8,294
Recurring | Derivative liabilities associated with convertible notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		4,890
Recurring | Common stock warrant liability
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		3,358
Recurring | Convertible preferred stock warrant liability
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Total liabilities measured at fair value		$1,233

Fair_Value_Measurements_Summar

Fair Value Measurements - Summary of Changes in Fair Value of Financial Instruments (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Extinguishment of warrant liability upon exercise of put option by warrant holder	($1,356)	$0	$0
Derivative liabilities associated with convertible notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value as of December 31	4,890	1,800
Fair value of financial instruments issued	1,050	5,750
Cash payments against Medicis settlement	0	0
Modification remeasurement		0
Change in fair value	-4,032	-2,660
Extinguishment of warrant liability upon exercise of put option by warrant holder	0
Balance upon conversion	-1,908
Fair value as of December 31	0	4,890
Derivative liabilities associated with the Medicis settlement
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value as of December 31	8,294	15,268
Fair value of financial instruments issued	0	0
Cash payments against Medicis settlement	-7,073	-6,927
Modification remeasurement		0
Change in fair value	320	-47
Extinguishment of warrant liability upon exercise of put option by warrant holder	0
Balance upon conversion	0
Fair value as of December 31	1,541	8,294
Common stock warrant liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value as of December 31	3,358	0
Fair value of financial instruments issued	981	2,737
Cash payments against Medicis settlement	0	0
Modification remeasurement		0
Change in fair value	2,151	621
Extinguishment of warrant liability upon exercise of put option by warrant holder	0
Balance upon conversion	-6,490
Fair value as of December 31	0	3,358
Convertible preferred stock warrant liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value as of December 31	1,233	351
Fair value of financial instruments issued	80	139
Cash payments against Medicis settlement	0	0
Modification remeasurement		1,168
Change in fair value	210	-425
Extinguishment of warrant liability upon exercise of put option by warrant holder	-82
Balance upon conversion	-1,441
Fair value as of December 31	$0	$1,233

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Details) (USD $)	Feb. 13, 2014
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]
Fair value of derivative	$7.10

Balance_Sheet_Components_Addit

Balance Sheet Components - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Balance Sheet Components [Abstract]
Depreciation expense	$2,051,000	$1,881,000	$1,777,000
Outstanding obligations related to construction-in-progress	500,000	1,800,000
Capitalized interest	$972,000	$453,000	$0

Balance_Sheet_Components_Sched

Balance Sheet Components - Schedule of Property and Equipment, Net (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$29,180	$22,504
Less: accumulated depreciation and amortization	-9,906	-8,189
Property and equipment, net	19,274	14,315
Research equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,914	9,045
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	477	496
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	534	451
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,833	3,632
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$13,422	$8,880

Balance_Sheet_Components_Sched1

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Balance Sheet Components [Abstract]
Prepaid expenses	$1,085	$531
Accounts receivable	300	225
Other current assets	239	69
Total prepaid expenses and other current assets	$1,624	$825

Balance_Sheet_Components_Sched2

Balance Sheet Components - Schedule of Accruals and Other Current Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Balance Sheet Components [Abstract]
Accrued compensation	$2,088	$689
Accrued professional service fees	577	367
Accrued manufacturing and quality control costs	361	0
Accrued clinical trial expenses	322	169
Accrued fixed assets	266	0
Accrued construction-in-progress obligations	60	1,757
Accrued interest on notes payable	23	478
Accrued initial public offering costs	0	506
Other current liabilities	448	195
Total accruals and other current liabilities	$4,145	$4,161

Balance_Sheet_Components_Sched3

Balance Sheet Components - Schedule of Other Non-Current Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Balance Sheet Components [Abstract]
Deferred initial public offering costs	$0	$2,812
Unamortized debt issuance costs	0	194
Prepaid expenses, non-current	29	0
Total other non-current assets	$29	$3,006

Notes_Payable_Hercules_Notes_P

Notes Payable - Hercules Notes Payable (Detail) (USD $)	1 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
		monthly_payment
Debt Instrument [Line Items]
Notes Payable		$2,641,000
Proceeds from notes payable		6,750,000	21,903,000	18,170,000
Unamortized debt discount		-6,000
Unamortized debt issuance costs		0	194,000
Hercules Notes Payable
Debt Instrument [Line Items]
Notes Payable		2,600,000
Proceeds from notes payable	22,000,000
Unamortized debt discount		-10,000	-40,000
Notes payable maturity		31-Mar-15
Interest rate, percentage		9.85%
Notes payable repayment start date		31-Jul-12
Notes payable repayment terms		33
Payment of notes payable principal and interest		800,000
Prepayment charge on end of term payment		500,000
End of term payment		400,000
Prepayment premium amount		15,000,000
Warrants issued to purchase shares		17,977
Exercise price per share		$66.75
Debt discount amortized		100,000
Recognition of interest expense from warrant related debt discount		40,000	100,000	40,000
Debt issuance costs		500,000
Amortization of debt issuance costs		200,000	200,000	200,000
Unamortized debt issuance costs		0	200,000
Hercules Notes Payable | Minimum
Debt Instrument [Line Items]
Prepayment premium percentage		1.00%
Hercules Notes Payable | Maximum
Debt Instrument [Line Items]
Prepayment premium percentage		4.00%
Hercules Notes Payable | Prime Rate
Debt Instrument [Line Items]
Plus (minus) difference from the prime rate		3.25%
Venture Debt
Debt Instrument [Line Items]
Repayment of debt	7,000,000
Unamortized debt discount	($579,000)

Notes_Payable_Essex_Capital_No

Notes Payable - Essex Capital Notes (Detail) (USD $)	12 Months Ended			1 Months Ended		2 Months Ended	1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	31-May-14	Jan. 31, 2014	Feb. 28, 2015	Dec. 17, 2014	Feb. 28, 2014	Dec. 20, 2013
Debt Instrument [Line Items]
Settlement of outstanding loan balance	$0	$32,008,000	$0
Interest expense for amortization of warrant	10,672,000	15,164,000	28,959,000
Unamortized debt discount	6,000			6,000
Repayment of notes payable	12,316,000	7,594,000	3,403,000
Interest paid	1,182,000	1,590,000	2,302,000
Total principal payments	2,641,000			2,641,000
Warrants
Debt Instrument [Line Items]
31-Dec-14	198,662			198,662
Essex Notes
Debt Instrument [Line Items]
Secured promissory notes, able to borrow (up to)										10,800,000
Interest rate, percentage									10.38%	11.50%
Short-term notes		2,500,000				2,500,000
Settlement of outstanding loan balance					1,100,000
31-Dec-14								44,753
Common stock shares purchased						12,345
Fair value of warrants		200,000
Debt issuance costs	30,000
Unamortized debt discount	0	200,000		0
Repayment of notes payable				3,900,000
Total principal payments								3,900,000
Essex Notes | Warrants
Debt Instrument [Line Items]
Interest expense for amortization of warrant	200,000	4,000
Essex Notes | Scenario, Forecast
Debt Instrument [Line Items]
Lease period							3 years
Percentage of original purchase amount of asset at end of lease							10.00%
Essex Notes | Subsequent Event
Debt Instrument [Line Items]
Equipment Purchased by Third Party, Increase During Period							100,000
Essex Notes | Subsequent Event | Scenario, Forecast
Debt Instrument [Line Items]
Equipment purchased by third party							9,800,000
Hercules Notes Payable
Debt Instrument [Line Items]
Interest rate, percentage	9.85%			9.85%
Debt issuance costs	500,000
Unamortized debt discount	10,000	40,000		10,000
Repayment of notes payable	9,200,000
Interest paid	400,000	0
Total principal payments	$2,600,000			$2,600,000

Notes_Payable_Summary_of_Aggre

Notes Payable - Summary of Aggregate Total Future Minimum Lease Payments under the Financing Obligation (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]
2015	$423
2016	423
2017	141
Total payments	$987

Notes_Payable_Summary_of_Futur

Notes Payable - Summary of Future Principal Payments under the Notes Payable (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]
2015	$2,641
Total principal payments	2,641
Less: debt discount	-6
Less: current portion	-2,635	-10,702
Long-term portion of notes payable	$0	$2,632

Convertible_Notes_Warrants_and2

Convertible Notes, Warrants, and Related Derivatives - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013	Feb. 28, 2014	Jan. 31, 2014	Dec. 31, 2013	31-May-11	Jan. 31, 2011	Oct. 31, 2013
Debt Instrument [Line Items]
Amortization of debt issuance cost	$203,000	$217,000	$300,000
Unamortized debt discount	0	194,000					194,000
Exercise price of warrants (in dollars per share)		$0.15	$1.15				$0.15
Amortization of debt discount	1,250,000	4,128,000	7,427,000
Unamortized debt discount	6,000
Gain (loss) on debt extinguishment	8,331,000	0	0
Interest expense	271,000	273,000	0
Interest expense, excluding amortization of debt discount	1,182,000	1,590,000	2,302,000
Series E-5
Debt Instrument [Line Items]
Offering price of convertible preferred stock (in dollars per share)		$22.43					$22.43
2011 Notes [Member]
Debt Instrument [Line Items]
Convertible debt		71,000,000	18,200,000				71,000,000	30,000,000	15,000,000
Percentage of equity held			5.00%
Percentage of Convertible Note holders required to consent to agreement amendment, at least		75.00%
Debt conversion price, percentage of offering price of convertible preferred stock		66.67%
Shares issued upon debt conversion (in shares)		4,748,484
Difference in the estimated fair value of the convertible preferred stock and the carrying value of the convertible debt, recorded as a capital contribution		32,000,000
Fair value of embedded derivative liability				0
Gain (loss) on embedded derivative liability				1,800,000
Debt issuance costs			43,000
Amortization of debt issuance cost		62,000	145,000
Unamortized debt discount	0		103,000
31-Dec-14			77,521
Fair value of warrants			153,000
Exercise price of warrants (in dollars per share)			$0.15
Unamortized debt discount		0					0
2011 Notes [Member] | Convertible Notes Payable, Related Party
Debt Instrument [Line Items]
Convertible debt			40,600,000
2011 Notes [Member] | Convertible Notes Payable, Related Party | Stockholders With Holdings of 5% or More
Debt Instrument [Line Items]
Convertible debt			30,900,000
2011 Notes, Warrant
Debt Instrument [Line Items]
Amortization of debt discount		214,000	260,000
Unamortized debt discount	0
2011 Notes, Embedded Derivative Liability
Debt Instrument [Line Items]
Fair value of embedded derivative liability		0					0
Amortization of debt discount		2,800,000	7,100,000
Unamortized debt discount	0	0					0
2013 Notes
Debt Instrument [Line Items]
Convertible debt					26,200,000					30,000,000
Shares issued upon debt conversion (in shares)					1,637,846
Fair value of embedded derivative liability					1,900,000					5,800,000
Gain (loss) on embedded derivative liability	4,000,000	900,000
Unamortized debt discount		7,200,000					7,200,000
31-Dec-14										409,450
Fair value of warrants		2,700,000					2,700,000
Amortization of debt discount		1,300,000
Amount borrowed						4,300,000	19,400,000
Interest rate, percentage										12.00%
Shares issued upon exercise of warrants (in shares)					405,594
Gain (loss) on debt extinguishment					8,300,000
Interest expense	9,600,000
Interest expense, excluding amortization of debt discount	300,000
2013 Notes, Warrant
Debt Instrument [Line Items]
Amortization of debt discount	400,000
2013 Notes, Embedded Derivative Liability
Debt Instrument [Line Items]
Amortization of debt discount	$600,000

Convertible_Notes_Warrants_and3

Convertible Notes, Warrants, and Related Derivatives - Fair Value Assumptions Using "Monte Carle" Simulation (Details) (2013 Notes)	0 Months Ended	12 Months Ended
	Oct. 31, 2013	Dec. 31, 2013
2013 Notes
Debt Instrument [Line Items]
Expected term (in years)	10 months 8 days	9 months 6 days
Discount rate	15.00%	16.50%
Maturity	5.00%	5.00%
Qualified financing	20.00%	5.00%
Initial public offering	60.00%	80.00%
Change in control	15.00%	10.00%

Interest_Expense_Summary_of_In

Interest Expense - Summary of Interest Expense by Cash and Non-Cash Components (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Income and Expenses [Abstract]
Cash related interest expense	($1,182)	($1,590)	($2,302)
Non-cash interest expense
Non-cash interest expense — debt issuance costs	-203	-490	-300
Non-cash interest expense — warrant and derivative related debt discounts	-650	-4,128	-7,427
Non-cash interest expense — convertible notes	-1,250	-9,409	-18,930
Loss on extinguishment of 2013 Notes	-8,331	0	0
Effective interest on financing obligation	-28	0	0
Capitalized interest	972	453	0
Total non-cash interest expense	-9,490	-13,574	-26,657
Total interest expense	($10,672)	($15,164)	($28,959)

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Extended term of lease	36 months
Tenant improvement allowance	$3,000,000
Total rent payments payable under lease agreement	72,800,000	53,618,000
Term of lease agreement	15 years
Rent expense		5,200,000	4,400,000	4,400,000
Purchase commitments		$15,100,000

Commitments_and_Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases (Detail) (USD $)	Dec. 31, 2014	Feb. 28, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
2015	$5,070
2016	5,222
2017	5,394
2018	5,578
2019 and thereafter	32,354
Total payments	$53,618	$72,800

Common_Stock_Additional_Inform

Common Stock - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	95,000,000	224,000,000
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, reserved for future issuance (in shares)	606,457	9,837,134
Preferred Stock
Class of Stock [Line Items]
Common stock, reserved for future issuance (in shares)	0	8,689,999
Employee Stock
Class of Stock [Line Items]
Common stock, reserved for future issuance (in shares)	174,661	0
Stock Compensation Plan
Class of Stock [Line Items]
Common stock, reserved for future issuance (in shares)	91,634	202,562
Stock Inducement Plan
Class of Stock [Line Items]
Common stock, reserved for future issuance (in shares)	141,500	0
Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	95,000,000
Common stock, par value (in dollars per share)	$0.00
Stock repurchase program, authorized amount (in shares)	$0	$3,333
Convertible preferred stock warrants
Class of Stock [Line Items]
Common stock, reserved for future issuance (in shares)	198,662	760,087
Convertible Preferred Stock
Class of Stock [Line Items]
Common stock, reserved for future issuance (in shares)	0	184,486

Convertible_Preferred_Stock_Ad

Convertible Preferred Stock - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended			0 Months Ended	1 Months Ended
	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 13, 2014	Mar. 31, 2013	Dec. 31, 2011	Feb. 28, 2013
Temporary Equity [Line Items]
Conversion of preferred stock to common stock	8,689,999
Conversion ratio	1
Shares issued		0	8,689,999
Shares outstanding		0	8,689,999	1,517,381			1,517,381
Proceeds from issuance of convertible preferred stock, net		$0	$40,646,000	$0
Capital contribution on the extinguishment of prior convertible preferred stock		0	74,894,000	0
Par value (in dollars per share)		$0.00	$0.00
Weighted average probability, market-based						0.6
Weighted average probability, income approach						0.4
Preferred stock dividends		0	177,000	0
Series E-1
Temporary Equity [Line Items]
Shares issued			387,241
Shares outstanding			387,241
Par value (in dollars per share)						$15
Preferred stock, par value (in dollars per share)						$0.75
Series E-2
Temporary Equity [Line Items]
Shares issued			585,559
Shares outstanding			585,559
Par value (in dollars per share)						$15
Preferred stock, par value (in dollars per share)						$1.05
Series E-3
Temporary Equity [Line Items]
Shares issued			1,150,341
Shares outstanding			1,150,341
Par value (in dollars per share)						$15
Preferred stock, par value (in dollars per share)						$1.95
Series E-4
Temporary Equity [Line Items]
Shares issued			4,748,468
Shares outstanding			4,748,468
Par value (in dollars per share)						$15
Preferred stock, par value (in dollars per share)						$12.60
Series E-5
Temporary Equity [Line Items]
Shares issued			1,818,390
Shares outstanding			1,818,390
Proceeds from issuance of convertible preferred stock, net			40,800,000
Share price			$22.43
Par value (in dollars per share)						$15
Preferred stock, par value (in dollars per share)						$33.60
Par value, weighted-average method (in dollars per share)						$22.50
Forward contract purchase commitment								2,100,000
Option, shares					93,333
Option, additional shares						7,911
Preferred stock dividends			$177,000
Series A
Temporary Equity [Line Items]
Shares issued upon conversion			1
Series B-1
Temporary Equity [Line Items]
Shares issued upon conversion			1
Series B-2
Temporary Equity [Line Items]
Shares issued upon conversion			1
Series C-1
Temporary Equity [Line Items]
Shares issued upon conversion			1
Series C-2
Temporary Equity [Line Items]
Shares issued upon conversion			1
Series C-3
Temporary Equity [Line Items]
Shares issued upon conversion			1
Series D
Temporary Equity [Line Items]
Shares issued upon conversion			0.4719

Convertible_Preferred_Stock_Ou

Convertible Preferred Stock - Outstanding (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, except Share data, unless otherwise specified
Temporary Equity [Line Items]
Shares Authorized	5,000,000	145,010,269
Shares issued	0	8,689,999
Shares outstanding	0	8,689,999	1,517,381	1,517,381
Liquidation Value	$0	$215,264
Series E-1
Temporary Equity [Line Items]
Shares Authorized		5,834,206
Shares issued		387,241
Shares outstanding		387,241
Liquidation Value per Share		$22.43
Liquidation Value		8,684
Series E-2
Temporary Equity [Line Items]
Shares Authorized		8,914,007
Shares issued		585,559
Shares outstanding		585,559
Liquidation Value per Share		$22.43
Liquidation Value		13,131
Series E-3
Temporary Equity [Line Items]
Shares Authorized		17,710,373
Shares issued		1,150,341
Shares outstanding		1,150,341
Liquidation Value per Share		$22.43
Liquidation Value		25,797
Series E-4
Temporary Equity [Line Items]
Shares Authorized		72,551,683
Shares issued		4,748,468
Shares outstanding		4,748,468
Liquidation Value per Share		$22.43
Liquidation Value		106,485
Series E-5
Temporary Equity [Line Items]
Shares Authorized		40,000,000
Shares issued		1,818,390
Shares outstanding		1,818,390
Liquidation Value per Share		$33.64
Liquidation Value		$61,167

Warrants_Additional_Informatio

Warrants - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2014	Dec. 31, 2014	31-May-14	Jan. 31, 2014	Dec. 17, 2014	Oct. 08, 2013	Mar. 31, 2013
				investor	warrant
Class of Warrant or Right [Line Items]
Revaluation of common stock warrant liability	$2,151,000	$621,000	$0
Loss on cash settlement	1,356,000	0	0
Exercise price of warrants (in dollars per share)		$0.15	$1.15
Fair value of common stock warrants issued	379,000	0	0
Essex Notes
Class of Warrant or Right [Line Items]
Fair value of Essex warrants								44,753
Convertible preferred stock warrants
Class of Warrant or Right [Line Items]
Number of shares underlying warrants	0	184,486			0	20,066	72,248
Revaluation of common stock warrant liability		1,233,000
Fair value of Essex warrants	198,662				198,662
Number of investors				2
Issuance of common stock upon net exercise of warrant				22,856
Fair value, number of days preceding				5 days
Loss on cash settlement				1,400,000
Expected term (in years)		6 years 6 months
Expected volatility		58.80%
Risk-free interest rate		2.10%
Warrants issued, principal amount									19,400,000
Fair value of warrants		1,233,000							2,700,000
Loss due to change in fair value	400,000	600,000
Convertible preferred stock warrants | Minimum
Class of Warrant or Right [Line Items]
Exercise price of warrants (in dollars per share)	$14.40				14.4
Convertible preferred stock warrants | Maximum
Class of Warrant or Right [Line Items]
Exercise price of warrants (in dollars per share)	$31.50				31.5
Convertible preferred stock warrants | Essex Notes
Class of Warrant or Right [Line Items]
Expected term (in years)	4 years
Expected volatility	53.00%
Risk-free interest rate	1.40%
Warrants issued					44,753
Fair value of common stock warrants issued	379,000
Convertible preferred stock warrants | Series C-2
Class of Warrant or Right [Line Items]
Shares issued upon conversion										1
Convertible preferred stock warrants | Series C-3
Class of Warrant or Right [Line Items]
Shares issued upon conversion										1
Convertible preferred stock warrants | Series E-3
Class of Warrant or Right [Line Items]
Number of shares underlying warrants		30,338
Shares issued upon conversion										0.4719
Exercise price of warrants (in dollars per share)		$31.50
Fair value of warrants		103,000
Convertible preferred stock warrants | Series E-4
Class of Warrant or Right [Line Items]
Number of shares underlying warrants		88,292
Shares issued upon conversion										0.224
Exercise price of warrants (in dollars per share)		$14.95
Fair value of warrants		574,000
Convertible preferred stock warrants | Series E-5
Class of Warrant or Right [Line Items]
Number of shares underlying warrants		65,856
Shares issued upon conversion										0.3359
Issuance of common stock upon net exercise of warrant				22,856
Number of warrant conversions				173,975
Exercise price of warrants (in dollars per share)		$22.02
Fair value of warrants		556,000
Convertible preferred stock warrants | Series E-5 | Minimum
Class of Warrant or Right [Line Items]
Exercise price of warrants (in dollars per share)				$14.95
Convertible preferred stock warrants | Series E-5 | Maximum
Class of Warrant or Right [Line Items]
Exercise price of warrants (in dollars per share)				$31.50
Convertible preferred stock warrants | Series E-5 | Essex Notes
Class of Warrant or Right [Line Items]
Number of shares underlying warrants							12,345
Fair value of warrants		100,000
Common Stock
Class of Warrant or Right [Line Items]
Issuance of common stock upon net exercise of warrant	10,613	52,481				10,613	1,158,443
Common Stock | Series E-5
Class of Warrant or Right [Line Items]
Number of shares underlying warrants		545,492
Exercise price of warrants (in dollars per share)		$0.15
Expected term (in years)		7 years
Expected volatility		57.10%
Risk-free interest rate		1.30%
Fair value of warrants		$4,700,000

Warrants_Schedule_of_Warrants_

Warrants - Schedule of Warrants (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	31-May-14	Jan. 31, 2014	Oct. 08, 2013
In Thousands, except Share data, unless otherwise specified
Class of Warrant or Right [Line Items]
Exercise Price Per Share	$0.15	$1.15
Convertible preferred stock warrants
Class of Warrant or Right [Line Items]
Number of Shares Underlying Warrants	184,486		0	20,066	72,248
Fair Value of Warrants	$1,233					$2,700
Convertible preferred stock warrants | Series E-3
Class of Warrant or Right [Line Items]
Number of Shares Underlying Warrants	30,338
Exercise Price Per Share	$31.50
Fair Value of Warrants	103
Convertible preferred stock warrants | Series E-4
Class of Warrant or Right [Line Items]
Number of Shares Underlying Warrants	88,292
Exercise Price Per Share	$14.95
Fair Value of Warrants	574
Convertible preferred stock warrants | Series E-5
Class of Warrant or Right [Line Items]
Number of Shares Underlying Warrants	65,856
Exercise Price Per Share	$22.02
Fair Value of Warrants	$556

Warrants_Assumptions_Using_Bla

Warrants - Assumptions Using Black-Scholes Model (Details) (Convertible preferred stock warrants)	12 Months Ended
	Dec. 31, 2013
Convertible preferred stock warrants
Class of Warrant or Right [Line Items]
Remaining contractual term (in years)	6 years 6 months
Expected volatility	58.80%
Risk-free interest rate	2.10%
Expected dividend rate	0.00%

Stock_Option_Plan_Additional_I

Stock Option Plan - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 22, 2014	Aug. 26, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, reserved for future issuance (in shares)	606,457	9,837,134
Stock-based compensation	$6,530,000	$548,000	$79,000
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, employee stock	$29.31	$8.23	$1.80
Unrecognized compensation cost	19,100,000	3,200,000	30,000
Unrecognized compensation cost, recognition period	3 years	3 years 2 months 12 days	1 year 9 months 18 days
Non-employee Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	13,333	76,666
Weighted average exercise price per share, nonemployee stock	$15.45	$8.74
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, reserved for future issuance (in shares)				200,000
Percentage of outstanding stock				1.00%
Number of shares available for grant, additional shares reserved				300,000
Stock-based compensation	500,000
Issued shares of common stock	25,339
2012 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance			339,302
Common stock, reserved for future issuance (in shares)		202,558
Expiration period	10 years
Award vesting period	4 years
Award vesting rights, percentage	25.00%
2012 Equity Incentive Plan | Incentive Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stockholder ownership percentage threshold	10.00%
2012 Equity Incentive Plan | Non-employee Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stockholder ownership percentage threshold	10.00%
2012 Equity Incentive Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common stock, percent	85.00%
2012 Equity Incentive Plan | Minimum | Incentive Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common stock, percent	100.00%
Purchase price of common stock, percent, stockholder over ownership percentage threshold	110.00%
2012 Equity Incentive Plan | Minimum | Non-employee Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common stock, percent	85.00%
Purchase price of common stock, percent, stockholder over ownership percentage threshold	110.00%
2014 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common stock that may be issued pursuant to the plan	1,000,000
Percentage of outstanding stock	4.00%
2014 Equity Incentive Plan | Incentive Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period	10 years
Number of common stock that may be issued pursuant to the plan	2,000,000
2014 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, reserved for future issuance (in shares)					325,000
Expiration period					10 years
Share price	$16.94	$11.40	$6.90
Intrinsic value of options exercised	$2,600,000	$40,000	$0
2014 Inducement Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance	141,500
Stock options granted	140,125
Weighted average exercise price per share, nonemployee stock	$22.52
Number of shares available for grant, additional shares reserved	325,000
2014 Inducement Plan | Vesting Period 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage					25.00%
2014 Inducement Plan | Vesting Period 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage					27.78%
2014 Inducement Plan | Vesting Period 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage					20.83%
2014 Inducement Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					3 years
2014 Inducement Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					4 years
2014 Inducement Plan | Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					4 years

Stock_Option_Plan_Summary_of_S

Stock Option Plan - Summary of Stock Option and Restricted Stock Award Activity (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share, exercised		$2.55
Restricted Stock Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Number of Shares Available for Grant [Roll Forward]
Restricted stock units, grants	-255,825
Forfeited	4,500
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted	255,825
Restricted stock units, forfeited	-4,500
2014 Equity Incentive Plan | Employee Stock Option and Restrcited Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award, Options, Number of Shares Available for Grant [Roll Forward]
Number of shares available for grant, beginning balance	202,558	32,985	24,281
Number of Shares Available for Grant, grants in period	-728,349	-992,213	-10,266
Number of shares underlying outstanding options, cancelled/forfeited	14,600	81,125	18,970
Number of shares available for grant, additional shares reserved	1,000,000	1,080,661
Restricted stock units, grants	-212,450
Forfeited	4,500
Number of shares underlying outstanding options, retired	-189,225
Number of shares available for grant, ending balance	91,634	202,558	32,985
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of shares underlying outstanding options, beginning balance	1,213,065	306,317	317,551
Number of shares underlying outstanding options, grants in period	728,349	992,213	10,266
Number of shares underlying outstanding options, exercises	-238,999	-4,340	-2,530
Number of shares underlying outstanding options, cancelled/forfeited	-14,600	-81,125	-18,970
Number of shares underlying outstanding options, ending balance	1,886,148	1,213,065	306,317
Number of shares underlying outstanding options, vested and expected to vest	1,809,590
Number of shares underlying outstanding options, exercisable	497,855
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted	212,450
Restricted stock units, forfeited	-4,500
Restricted stock units, retired	-9,617
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share, beginning balance	$7.65	$3.45	$3.45
Weighted average exercise price per share, granted	$30.21	$8.80	$1.35
Weighted average exercise price per share, exercised	$5.96	$2.55	$2.55
Weighted average exercise price per share, cancelled/forfeited	$26.89	$6.42	$2.70
Weighted average exercise price per share, ending balance	$17.90	$7.65	$3.45
Weighted average exercise price per share, vested and expected to vest	$17.94
Weighted average exercise price per share, exercisable	$11.29
Weighted average remaining contractual life, outstanding (in years)	8 years 7 months 10 days
Weighted average remaining contractual life, vested and expected to vest (in years)	8 years 7 months 10 days
Weighted average remaining contractual life, exercisable (in years)	7 years 5 months 9 days
Aggregate intrinsic value, outstanding	$8,645
Aggregate intrinsic value, vested and expected to vest	8,573
Aggregate intrinsic value, exercisable	4,011
2014 Inducement Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award, Options, Number of Shares Available for Grant [Roll Forward]
Number of Shares Available for Grant, grants in period	-140,125
Number of shares available for grant, additional shares reserved	325,000
Number of shares available for grant, ending balance	141,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of shares underlying outstanding options, grants in period	140,125
Number of shares underlying outstanding options, ending balance	183,500
Number of shares underlying outstanding options, vested and expected to vest	140,125
Number of shares underlying outstanding options, exercisable	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share, granted	$22.52
Weighted average exercise price per share, ending balance	$22.52
Weighted average exercise price per share, vested and expected to vest	$22.52
Weighted average exercise price per share, exercisable	$0
Weighted average remaining contractual life, outstanding (in years)	9 years 8 months 5 days
Weighted average remaining contractual life, vested and expected to vest (in years)	9 years 8 months 5 days
Weighted average remaining contractual life, exercisable (in years)	0 years
Aggregate intrinsic value, outstanding	0
Aggregate intrinsic value, vested and expected to vest	0
Aggregate intrinsic value, exercisable	$0
2014 Inducement Plan | Restricted Stock Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Number of Shares Available for Grant [Roll Forward]
Number of Shares Available for Grant, grants in period	-43,375
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of shares underlying outstanding options, grants in period	43,375
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share, granted	$0

Stock_Option_Plan_Stock_Option

Stock Option Plan - Stock Options Outstanding and Exercisable (Details) (Employee Stock Option, USD $)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options	1,818,323
Options Exercisable	497,855
$0.45 - 6.60
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	$0.45
Exercise price range, upper range limit	$6.60
Number of Options	141,874
Weighted- Average Remaining Contractual Life (In Years)	4 years 5 months 27 days
Options Exercisable	138,645
$8.70
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, upper range limit	$8.70
Number of Options	627,345
Weighted- Average Remaining Contractual Life (In Years)	8 years 4 months 10 days
Options Exercisable	218,165
$8.85
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, upper range limit	$8.85
Number of Options	3,333
Weighted- Average Remaining Contractual Life (In Years)	8 years 9 months 4 days
Options Exercisable	971
$9.15
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, upper range limit	$9.15
Number of Options	195,930
Weighted- Average Remaining Contractual Life (In Years)	8 years 11 months 5 days
Options Exercisable	42,813
$15.45 - 22.97
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	$15.45
Exercise price range, upper range limit	$22.97
Number of Options	184,308
Weighted- Average Remaining Contractual Life (In Years)	9 years 7 months 21 days
Options Exercisable	14,707
$24.58 - 31.1
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	$24.58
Exercise price range, upper range limit	$31.10
Number of Options	180,833
Weighted- Average Remaining Contractual Life (In Years)	9 years 2 months 19 days
Options Exercisable	12,660
$32.22
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, upper range limit	$32.22
Number of Options	479,300
Weighted- Average Remaining Contractual Life (In Years)	9 years 4 months 17 days
Options Exercisable	69,894
$32.81 - 33.45
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	$32.81
Exercise price range, upper range limit	$33.45
Number of Options	1,800
Weighted- Average Remaining Contractual Life (In Years)	9 years 6 months 7 days
Options Exercisable	0
$34.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, upper range limit	$34
Number of Options	1,200
Weighted- Average Remaining Contractual Life (In Years)	9 years 6 months
Options Exercisable	0
$34.27
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, upper range limit	$34.27
Number of Options	2,400
Weighted- Average Remaining Contractual Life (In Years)	9 years 3 months 26 days
Options Exercisable	0

Stock_Option_Plan_Summary_of_R

Stock Option Plan - Summary of Restricted Stock Award Activity (Details) (Restricted Stock, USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, beginning balance	0
Granted	255,825
Vested	0
Forfeited	-4,500
Outstanding, ending balance	251,325
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding, beginning balance	$0
Granted	$29.47
Vested	$0
Forfeited	$26.89
Outstanding, ending balance	$29.51
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value [Abstract]
Outstanding, beginning balance	$0
Outstanding, ending balance	$4,257

Stock_Option_Plan_Fair_Value_A

Stock Option Plan - Fair Value Assumptions (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining contractual term (in years)	6 months
Expected volatility	46.80%
Risk-free interest rate	0.10%
Expected dividend rate	0.00%
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining contractual term (in years)	6 years	6 years	5 years 10 months 24 days
Expected volatility	57.40%	59.10%	56.90%
Risk-free interest rate	1.90%	1.30%	0.80%
Expected dividend rate	0.00%	0.00%	0.00%
Non-employee Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining contractual term (in years)	7 years 3 months 18 days	9 years	6 years 9 months 18 days
Expected volatility	56.10%	58.80%	57.00%
Risk-free interest rate	2.10%	2.70%	1.20%
Expected dividend rate	0.00%	0.00%	0.00%

Stock_Option_Plan_Schedule_of_

Stock Option Plan - Schedule of Stock-based Compensation Expense (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock based compensation expense	$6,530	$548	$79
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock based compensation expense	2,357	194	48
Sales, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock based compensation expense	$4,173	$354	$31

Net_Income_Loss_per_Share_Attr2

Net Income (Loss) per Share Attributable to Common Stockholders - Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net loss	($14,212,000)	($13,977,000)	($13,302,000)	($21,426,000)	($10,083,000)	($8,879,000)	($11,829,000)	($21,657,000)	($62,917,000)	($52,448,000)	($58,259,000)
Capital contribution on the extinguishment of prior convertible preferred stock									0	74,894,000	0
Deemed dividend on the issuance of Series E-5 convertible preferred stock									0	-177,000	0
Undistributed earnings allocated to preferred stockholders									0	-8,133,000	0
Net income (loss) attributable to common stockholders, basic	-14,212,000	-13,977,000	-13,302,000	-21,426,000	-13,987,000	-12,789,000	-15,750,000	5,216,000	-62,917,000	258,000	-58,259,000
Adjustments to net income (loss) for dilutive securities										825,000	0
Net income (loss) attributable to common stockholders, diluted	-14,212,000	-13,977,000	-13,302,000	-21,426,000	-13,987,000	-12,789,000	-15,750,000	13,307,000	-62,917,000	1,083,000	-58,259,000
Net income (loss) per share attributable to common stockholders
Basic (in dollars per share)	($0.60)	($0.60)	($0.69)	($1.93)	($53.63)	($55.90)	($75.25)	$25.54	($3.24)	$1.17	($290.48)
Diluted (in dollars per share)	($0.60)	($0.60)	($0.69)	($1.93)	($47.11)	($55.90)	($75.25)	$21	($3.24)	$1.05	($290.48)
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders:
Basic (in shares)									19,391,523	220,220	200,560
Stock options (in shares)									0	167,655	0
Warrants to purchase common stock (in shares)									0	641,275	0
Diluted (in shares)									19,391,523	1,029,150	200,560
Series E convertible preferred stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Noncumulative dividend on Series E convertible preferred stock									$0	($13,878,000)	$0

Net_Income_Loss_per_Share_Attr3

Net Income (Loss) per Share Attributable to Common Stockholders - Summary of Common Stock Equivalents Excluded from Computation of Diluted Net Income (Loss) Per Share (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net income (loss) per share	1,818,323	0	306,312
Convertible preferred stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net income (loss) per share	0	184,486	82,262
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net income (loss) per share	198,662	0	267,166
Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net income (loss) per share	0	8,689,999	1,741,432

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Contingency [Line Items]
Increase (decrease) in valuation allowance for deferred tax assets	$16,200,000	$10,500,000
Excess stock option deductions	2,100,000
Unrecognized tax benefits	1,268,000	2,288,000	2,012,000	1,912,000
Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards, amount	247,100,000
Net operating loss carryforwards derecognized	1,400,000
California
Income Tax Contingency [Line Items]
Net operating loss carryforwards, amount	158,300,000
New Jersey
Income Tax Contingency [Line Items]
Net operating loss carryforwards, amount	174,800,000
Research and development tax credits | Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards, amount	4,800,000
Research and development credit carryforwards	400,000
Unrecognized tax benefits	1,268,000	2,288,000
Research and development tax credits | California
Income Tax Contingency [Line Items]
Research and development credit carryforwards	$4,800,000

Income_Taxes_Deferred_Tax_Asse

Income Taxes - Deferred Tax Assets and Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Tax Assets (Liabilities)
Stock based compensation	$93,260	$78,169
Accruals and reserves	2,458	1,854
Stock based compensation	1,602	86
Tax credits	2,623	5,760
Fixed and intangible assets	1,771	2,057
Valuation Allowance	-101,714	-85,488
Total deferred tax assets	0	2,438
Debt discount	0	-2,438
Total deferred tax liabilities	0	-2,438
Net deferred tax assets	$0	$0

Income_Taxes_Effective_Tax_Rat

Income Taxes - Effective Tax Rate Reconciliation (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax (benefit) at statutory federal rate	($21,392)	($17,832)	($19,808)
State Tax (benefit) — net of federal benefit	79	849	-3,398
Permanent differences	660	3,931	8,887
Debt discount	756	2,888	0
Research and development credits	3,137	-642	-197
Other	537	284	51
Change in valuation allowance	16,226	10,522	14,465
Provision for taxes	$3	$0	$0

Income_Taxes_Unrecognized_Tax_

Income Taxes - Unrecognized Tax Benefits (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance	$2,288	$2,012	$1,912
Additions for current tax positions	196	276	100
Decrease for prior tax positions	-1,216
Balance	$1,268	$2,288	$2,012

Defined_Contribution_Plan_Addi

Defined Contribution Plan - Additional Information (Details)	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Defined contribution plan, age over which employees are covered	21 years

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Details) (USD $)	1 Months Ended	0 Months Ended			12 Months Ended
	Feb. 28, 2015	Jan. 30, 2015	Jan. 28, 2015	Feb. 26, 2015	Dec. 31, 2014	Mar. 04, 2015
Essex Notes | Subsequent Event
Subsequent Event [Line Items]
Equipment purchased by third party, increase during period	$100,000
Essex Notes | Scenario, Forecast
Subsequent Event [Line Items]
Lease period	3 years
Percentage of original purchase amount of asset at end of lease	10.00%
Essex Notes | Scenario, Forecast | Subsequent Event
Subsequent Event [Line Items]
Equipment purchased by third party	9,800,000
2014 Equity Incentive Plan | Subsequent Event
Subsequent Event [Line Items]
Aggregate intrinsic value, outstanding		1,700,000	4,700,000
Employee Stock Option | Subsequent Event
Subsequent Event [Line Items]
Stock options granted		79,450	423,788
Employee Stock Option | Subsequent Event | Board of Directors Chairman
Subsequent Event [Line Items]
Stock options granted				18,000
Weighted average exercise price per share, granted				$16.46
Stock options granted, grant date intrinsic value				100,000
Award vesting period				1 year
Restricted Stock
Subsequent Event [Line Items]
Restricted stock awards granted					255,825
Restricted Stock | Subsequent Event
Subsequent Event [Line Items]
Restricted stock awards granted		65,300	74,786
Market Issuance Sales Agreement | Subsequent Event
Subsequent Event [Line Items]
Authorized aggregate offering price						$50,000,000
Commission percentage						3.00%

Quarterly_Results_of_Operation2

Quarterly Results of Operations (Unaudited) - Additional Information (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data [Abstract]
Revenue	$75	$75	$75	$158	$309	$158	$75	$75	$383	$617	$717
Net loss	-14,212	-13,977	-13,302	-21,426	-10,083	-8,879	-11,829	-21,657	-62,917	-52,448	-58,259
Net income (loss) attributable to common stockholders, basic	-14,212	-13,977	-13,302	-21,426	-13,987	-12,789	-15,750	5,216	-62,917	258	-58,259
Net income (loss) attributable to common stockholders, diluted	($14,212)	($13,977)	($13,302)	($21,426)	($13,987)	($12,789)	($15,750)	$13,307	($62,917)	$1,083	($58,259)
Net income (loss) attributable to common stockholders, basic (in dollars per share)	($0.60)	($0.60)	($0.69)	($1.93)	($53.63)	($55.90)	($75.25)	$25.54	($3.24)	$1.17	($290.48)
Net income (loss) attributable to common stockholders, diluted (in dollars per share)	($0.60)	($0.60)	($0.69)	($1.93)	($47.11)	($55.90)	($75.25)	$21	($3.24)	$1.05	($290.48)