Neurocrine Biosciences (NBIX) 10-K 9 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Jan. 26, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	NBIX
Entity Registrant Name	NEUROCRINE BIOSCIENCES INC
Entity Central Index Key	914475
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		77,163,348
Entity Public Float			$825,571,712

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$31,014	$44,789
Short-term investments, available-for-sale	162,795	100,950
Other current assets	4,394	2,723
Total current assets	198,203	148,462
Property and equipment, net	2,507	1,771
Long-term investments, available-for-sale	37,492	0
Restricted cash	4,831	4,443
Total assets	243,033	154,676
Current liabilities:
Accounts payable	246	101
Accrued liabilities	11,508	7,955
Current portion of deferred rent	119	0
Current portion of cease-use liability	467	416
Current portion of deferred gain on sale of real estate	3,324	3,227
Total current liabilities	15,664	11,699
Deferred gain on sale of real estate	14,322	17,645
Deferred rent	1,877	1,982
Cease-use liability	2,211	2,680
Other liabilities	260	260
Total liabilities	34,334	34,266
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.001 par value; 110,000,000 shares authorized; issued and outstanding shares were 76,465,942 and 67,351,195 at December 31, 2014 and 2013, respectively	76	67
Additional paid-in capital	1,035,205	886,101
Accumulated other comprehensive (loss) gain	-277	5
Accumulated deficit	-826,305	-765,763
Total stockholders' equity	208,699	120,410
Total liabilities and stockholders' equity	$243,033	$154,676

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	110,000,000	110,000,000
Common stock, shares issued	76,465,942	67,351,195
Common stock, shares outstanding	76,465,942	67,351,195

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive (Loss) Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Sponsored research and development	$0	$0	$18,897
Milestones and license fees	0	2,919	34,243
Total revenues	0	2,919	53,140
Operating expenses:
Research and development	46,425	39,248	37,163
General and administrative	17,986	13,349	13,437
Cease-use expense	0	0	1,092
Total operating expenses	64,411	52,597	51,692
(Loss) income from operations	-64,411	-49,678	1,448
Other income:
(Loss) gain on sale/disposal of assets	-4	37	32
Deferred gain on real estate	3,226	3,133	3,042
Investment income, net	629	402	489
Other income, net	18	16	14
Total other income	3,869	3,588	3,577
Net (loss) income	-60,542	-46,090	5,025
Net (loss) income per common share:
Basic	($0.81)	($0.69)	$0.08
Diluted	($0.81)	($0.69)	$0.08
Shares used in the calculation of net (loss) income per common share:
Basic	74,577	66,989	65,619
Diluted	74,577	66,989	66,946
Other comprehensive (loss) income:
Net (loss) income	-60,542	-46,090	5,025
Net unrealized (losses) gains on available-for-sale securities	-282	7	85
Comprehensive (loss) income	($60,824)	($46,083)	$5,110

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive (Loss) Gain	Accumulated Deficit
In Thousands
Beginning balance at Dec. 31, 2011	$60,081	$55	$784,811	($87)	($724,698)
Beginning balance (in shares) at Dec. 31, 2011		55,263
Net income (loss)	5,025	0	0	0	5,025
Unrealized gains (losses) on investments	85	0	0	85	0
Share-based compensation	5,479	0	5,479	0	0
Issuance of common stock for restricted share units vested	0	0	0	0	0
Issuance of common stock for restricted share units vested (in shares)		50
Issuance of common stock for option exercises	731	0	731	0	0
Issuance of common stock for option exercises (in shares)	209	209
Issuance of common stock, net of offering costs	82,971	11	82,960	0	0
Issuance of common stock, net of offering costs (in shares)		10,925
Ending balance at Dec. 31, 2012	154,372	66	873,981	-2	-719,673
Ending balance (in shares) at Dec. 31, 2012		66,447
Net income (loss)	-46,090	0	0	0	-46,090
Unrealized gains (losses) on investments	7	0	0	7	0
Share-based compensation	6,819	0	6,819	0	0
Issuance of common stock for option exercises	5,302	1	5,301	0	0
Issuance of common stock for option exercises (in shares)	904	904
Ending balance at Dec. 31, 2013	120,410	67	886,101	5	-765,763
Ending balance (in shares) at Dec. 31, 2013		67,351
Net income (loss)	-60,542	0	0	0	-60,542
Unrealized gains (losses) on investments	-282	0	0	-282	0
Share-based compensation	10,382	0	10,382	0	0
Issuance of common stock for restricted share units vested	0	0	0	0	0
Issuance of common stock for restricted share units vested (in shares)		93
Issuance of common stock for option exercises	5,560	1	5,559	0	0
Issuance of common stock for option exercises (in shares)	1,135	1,022
Issuance of common stock, net of offering costs	133,171	8	133,163	0	0
Issuance of common stock, net of offering costs (in shares)		8,000
Ending balance at Dec. 31, 2014	$208,699	$76	$1,035,205	($277)	($826,305)
Ending balance (in shares) at Dec. 31, 2014		76,466

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 FLOW FROM OPERATING ACTIVITIES
Net (loss) income	($60,542)	($46,090)	$5,025
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Depreciation and amortization	827	671	657
Gain on sale of assets, net	-3,222	-3,170	-3,074
Cease-use expense	0	0	1,092
Deferred revenues	0	-2,919	-34,242
Deferred rent	14	142	305
Amortization of premiums on investments	3,792	2,843	3,135
Non-cash share-based compensation expense	10,382	6,819	5,479
Change in operating assets and liabilities:
Accounts receivable and other assets	-1,671	13,528	-12,878
Cease-use liability	-418	-590	-263
Other liabilities	0	108	27
Accounts payable and accrued liabilities	3,698	-949	-557
Net cash used in operating activities	-47,140	-29,607	-35,294
CASH FLOW FROM INVESTING ACTIVITIES
Purchases of investments	-257,544	-145,328	-166,313
Sales/maturities of investments	154,133	151,281	132,520
Deposits and restricted cash	-388	-108	-29
Proceeds from sales of property and equipment	45	40	32
Purchases of property and equipment	-1,612	-545	-971
Net cash (used in) provided by investing activities	-105,366	5,340	-34,761
CASH FLOW FROM FINANCING ACTIVITIES
Issuance of common stock	138,731	5,302	83,702
Net cash provided by financing activities	138,731	5,302	83,702
Net change in cash and cash equivalents	-13,775	-18,965	13,647
Cash and cash equivalents at beginning of the year	44,789	63,754	50,107
Cash and cash equivalents at end of the year	31,014	44,789	63,754
SUPPLEMENTAL DISCLOSURES
Taxes paid	$0	$0	$0

ORGANIZATION_AND_SUMMARY_OF_SI

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	NOTE 1. ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Business Activities. Neurocrine Biosciences, Inc. (the Company or Neurocrine) was incorporated in California in 1992 and reincorporated in Delaware in 1996. The Company discovers and develops innovative and life-changing pharmaceuticals, in diseases with high unmet medical needs, through its novel research and development (R&D) platform, focused on neurological and endocrine based diseases and disorders. The Company’s two lead late-stage clinical programs are elagolix, a gonadotropin-releasing hormone (GnRH) antagonist for women’s health that is partnered with AbbVie Inc. (AbbVie), and a wholly owned vesicular monoamine transporter 2 (VMAT2) inhibitor for the treatment of movement disorders.
	Neurocrine Continental, Inc., is a Delaware corporation and a wholly owned subsidiary of the Company and is inactive. The Company also has two wholly-owned Irish subsidiaries, Neurocrine Therapeutics, Ltd. and Neurocrine Europe, Ltd. which were formed during December 2014.
	Principles of Consolidation. The consolidated financial statements include the accounts of Neurocrine as well as its wholly owned subsidiaries. The Company does not have any significant interests in any variable interest entities. All intercompany transactions and balances have been eliminated in consolidation.
	Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the financial statements and the accompanying notes. Actual results could differ from those estimates.
	Cash Equivalents. The Company considers all highly liquid investments that are readily convertible into cash and have an original maturity of three months or less at the time of purchase to be cash equivalents.
	Short-Term and Long-Term Investments Available-for-Sale. Certain investments are classified as available-for-sale and, in accordance with authoritative guidance, are carried at fair value, with the unrealized gains and losses reported in other comprehensive (loss) income. The amortized cost of debt securities in this category is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included in investment income. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on available-for-sale securities are included in other income or expense. The cost of securities sold is based on the specific identification method. Interest and dividends on securities classified as available-for-sale are included in investment income.
	Concentration of Credit Risk. Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents and investments. The Company has established guidelines to limit its exposure to credit risk by placing investments with high credit quality financial institutions, diversifying its investment portfolio and placing investments with maturities that maintain safety and liquidity.
	Collaboration Agreements. During the years ended December 31, 2013 and 2012 collaborative R&D agreements accounted for all of the Company’s revenue.
	Property and Equipment. Property and equipment are stated at cost and depreciated over the estimated useful lives of the assets using the straight-line method. Equipment is depreciated over an average estimated useful life of three to seven years. Leasehold improvements are depreciated over the shorter of their estimated useful lives or the remaining lease term.
	Industry Segment and Geographic Information. The Company operates in a single industry segment – the discovery and development of therapeutics for the treatment of neurological and endocrine based diseases and disorders. The Company had no foreign based operations during any of the years presented.
	Impairment of Long-Lived Assets. The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. If indicators of impairment exist, the Company assesses the recoverability of the affected long-lived assets by determining whether the carrying value of such assets can be recovered through undiscounted future operating cash flows. If the carrying amount is not recoverable, the Company measures the amount of any impairment by comparing the carrying value of the asset to the present value of the expected future cash flows associated with the use of the asset.
	Fair Value of Financial Instruments. Financial instruments, including cash and cash equivalents, accounts receivable, accounts payable, and accrued liabilities, are carried at cost, which management believes approximates fair value because of the short-term maturity of these instruments.
	Research and Development Expenses. R&D expenses consists primarily of salaries, payroll taxes, employee benefits, and share-based compensation charges, for those individuals involved in ongoing R&D efforts; as well as scientific contractor fees, preclinical and clinical trial costs, R&D facilities costs, laboratory supply costs, and depreciation of scientific equipment. All such costs are charged to R&D expense as incurred. These expenses result from the Company’s independent R&D efforts as well as efforts associated with collaborations and in-licensing arrangements. In addition, the Company funds R&D at other companies and research institutions under agreements, which are generally cancelable. The Company reviews and accrues clinical trial expenses based on work performed, which relies on estimates of total costs incurred based on patient enrollment, completion of patient studies and other events. The Company follows this method since reasonably dependable estimates of the costs applicable to various stages of a research agreement or clinical trial can be made. Accrued clinical costs are subject to revisions as trials progress. Revisions are charged to expense in the period in which the facts that give rise to the revision become known.
	Share-Based Compensation. The Company estimates the fair value of stock options using the Black-Scholes option pricing model on the date of grant. Restricted stock units are valued based on the closing price of the Company’s common stock on the date of grant. The fair value of equity instruments expected to vest are recognized and amortized on a straight-line basis over the requisite service period of the award, which is generally three to four years; however, certain provisions in the Company’s equity compensation plans provide for shorter vesting periods under certain circumstances. Additionally, the Company has granted certain performance-based equity awards that vest upon the achievement of certain pre-defined Company-specific performance criteria. Expense related to these performance-based equity awards is generally recognized upon achievement of the specific performance criteria.
	Investment Income, net. Investment income, net is comprised of interest and dividends earned on cash, cash equivalents and investments as well as gains and losses realized from activity in the Company’s investment portfolio. The following table presents certain information related to the components of investment income (in thousands):
		Years Ended December 31,
		2014		2013		2012
	Interest income		629		400		489
	Realized gains, net		—		2		—
	Total	$	629	$	402	$	489
	Net (Loss) Income Per Share. The Company computes basic net (loss) income per share using the weighted average number of common shares outstanding during the period. Diluted net income per share is based upon the weighted average number of common shares and potentially dilutive securities (common share equivalents) outstanding during the period. Common share equivalents outstanding, determined using the treasury stock method, are comprised of shares that may be issued under the Company’s stock option agreements. Common share equivalents are excluded from the diluted net loss per share calculation because of their anti-dilutive effect.
	Due to the net loss position in 2014 and 2013, approximately 2.9 million and 2.1 million, respectively, of common share equivalents were excluded from the diluted common shares outstanding. At December 31, 2012, the Company had approximately 1.3 million of additional common share equivalents outstanding that were included in the diluted income per share calculation. For the years ended December 31, 2014, 2013 and 2012, there were employee stock options, calculated on a weighted average basis, to purchase 1.0 million, 0.3 million and 2.2 million shares of our common stock with an exercise price greater than the average market price of the underlying common shares.
	Impact of Recently Issued Accounting Standards. In May 2014, the Financial Accounting Standards Board (FASB) amended the existing accounting standards for revenue recognition. The amendments are based on the principle that revenue should be recognized to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for said goods or services. The Company is required to adopt the amendments beginning in 2017. Early adoption is not permitted. The amendments may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized as of the date of initial application. The Company is currently evaluating the impact that these amendments will have on its consolidated financial statements.
	In July 2013, the FASB issued guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013, with an option for early adoption. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements.

REVENUE_RECOGNITION_AND_SIGNIF

REVENUE RECOGNITION AND SIGNIFICANT COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENTS	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
REVENUE RECOGNITION AND SIGNIFICANT COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENTS	NOTE 2. REVENUE RECOGNITION AND SIGNIFICANT COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENTS
	Revenue Recognition Policy. Revenues under collaborative agreements and grants are recognized as research costs are incurred over the period specified in the related agreement or as the services are performed. These agreements are on a best-efforts basis, do not require scientific achievement as a performance obligation and provide for payment to be made when costs are incurred or the services are performed. All fees are nonrefundable to the collaborators. Prior to the revised multiple element guidance adopted by the Company on January 1, 2011, upfront, nonrefundable payments for license fees, grants, and advance payments for sponsored research revenues received in excess of amounts earned were classified as deferred revenue and recognized as income over the contract or development period. Estimating the duration of the development period includes continual assessment of development stages and regulatory requirements. If and when the Company enters into a new collaboration agreement or materially modifies an existing collaboration agreement, the Company will be required to apply the new multiple element guidance. Milestone payments are recognized as revenue upon achievement of pre-defined scientific events, which require substantive effort, and for which achievement of the milestone was not readily assured at the inception of the agreement.
	AbbVie Inc. (AbbVie). In June 2010, the Company announced an exclusive worldwide collaboration with AbbVie, to develop and commercialize elagolix and all next-generation GnRH antagonists (collectively, GnRH Compounds) for women’s and men’s health. AbbVie made an upfront payment of $75 million and has agreed to make additional development and regulatory event based payments of up to $480 million and up to an additional $50 million in commercial event based payments. The Company has assessed event based payments under the revised authoritative guidance for research and development milestones and determined that event based payments prior to commencement of a Phase III clinical study, as defined in the agreement, meet the definition of a milestone in accordance with authoritative guidance as (1) they are events that can only be achieved in part on the Company’s past performance, (2) there is substantive uncertainty at the date the arrangement was entered into that the event will be achieved and (3) they result in additional payments being due to the Company. Development and regulatory event based payments subsequent to the commencement of a Phase III clinical study, however, currently do not meet these criteria as their achievement is based on the performance of AbbVie. As of December 31, 2014, $500 million remains outstanding in future event based payments under the agreement. However, none of the remaining event based payments meet the definition of a milestone in accordance with authoritative accounting guidance.
	Under the terms of the agreement, AbbVie is responsible for all third-party development, marketing and commercialization costs. The Company received funding for certain internal collaboration expenses which included reimbursement from AbbVie for internal and external expenses related to the GnRH Compounds through the end of 2012. The Company will be entitled to a percentage of worldwide sales of GnRH Compounds for the longer of ten years or the life of the related patent rights. Under the terms of the Company’s agreement with AbbVie, the collaboration effort between the parties to advance GnRH Compounds towards commercialization was governed by a joint development committee with representatives from both the Company and AbbVie. AbbVie may terminate the collaboration at its discretion upon 180 days’ written notice to the Company. In such event, the Company would be entitled to specified payments for ongoing clinical development and related activities and all GnRH Compound product rights would revert to the Company. The Company’s participation in the joint development committee was determined to be a substantive deliverable under the contract, and therefore, the upfront payment was deferred and recognized over the term of the joint development committee, which was completed, as scheduled, in December 2012. During 2012, the Company recorded $13.1 million in revenue related to completion of the collaborative development period which is included as part of sponsored research and development revenue.
	There was no revenue recognized in 2014 or 2013 related to this collaboration. During the year ended December 31, 2012 the Company recognized $46.9 million in revenue under the AbbVie collaboration agreement, $29.1 million from the amortization of up-front license fees and $17.8 million from sponsored research and development.
	Dainippon Sumitomo Pharma Co., Ltd. (DSP). In October 2007, the Company entered into an exclusive license agreement with DSP, under which the Company licensed rights to indiplon to DSP and agreed to collaborate with DSP on the development and commercialization of indiplon in Japan. Pursuant to the license agreement, among other things, the Company received an up-front license fee of $20 million. The Company is also eligible to receive additional event based payments upon specified future events related to the development and commercialization of indiplon in Japan. Should all event based payments be achieved, the Company may be entitled to payments totaling an additional $115 million. Event based payments under the DSP agreement do not meet the criteria of a milestone in accordance with the authoritative guidance as they are based on the performance of DSP. Additionally, the Company is entitled to royalties from DSP on future sales of indiplon in Japan. For each of the years ended December 31, 2013 and 2012, the Company recognized into revenue $2.9 million of the upfront license fee under the DSP agreement. All performance obligations pursuant to the contract were completed during 2013.

INVESTMENTS

INVESTMENTS	12 Months Ended
	Dec. 31, 2014
Investments Schedule [Abstract]
INVESTMENTS	NOTE 3. INVESTMENTS
	Available-for-sale securities are carried at fair value, with the unrealized gains and losses reported in comprehensive (loss) income. The amortized cost of debt securities in this category is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included in investment income. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on available-for-sale securities are included in other income or expense. The cost of securities sold is based on the specific identification method. Interest and dividends on securities classified as available-for-sale are included in investment income.
	Investments at December 31, 2014 and 2013 consisted of the following (in thousands):
			Years Ended
			December 31,
			2014		2013
	Certificates of deposit		$	17,438	$	11,012
	Commercial paper			7,498		4,997
	Corporate debt securities			174,323		77,441
	Securities of government-sponsored entities			1,028		7,500
	Total investments		$	200,287	$	100,950
	The following is a summary of investments classified as available-for-sale securities (in thousands):
			Contractual		Amortized			Gross		Gross			Aggregate
			Maturity		Cost			Unrealized		Unrealized			Estimated
			(in years)					Gains(1)		Losses(1)			Fair
													Value
	December 31, 2014:
	Classified as current assets:
	Certificates of deposit			Less than 1	$	9,072		$	—	$	(6	)	$	9,066
	Commercial paper			Less than 1		7,497			1		—			7,498
	Corporate debt securities			Less than 1		145,321			5		(123	)		145,203
	Securities of government-sponsored entities			Less than 1		1,029			—		(1	)		1,028
	Total short-term available-for-sale securities				$	162,919		$	6	$	(130	)	$	162,795
	Classified as non-current assets:
	Certificates of deposit			1 to 2	$	8,400		$	—	$	(28	)	$	8,372
	Corporate debt securities			1 to 2		29,245			—		(125	)		29,120
	Total long-term available-for-sale securities				$	37,645		$	—	$	(153	)	$	37,492
	December 31, 2013:
	Classified as current assets:
	Certificates of deposit			Less than 1	$	11,018		$	1	$	(7	)	$	11,012
	Commercial paper			Less than 1		4,997			—		—			4,997
	Corporate debt securities			Less than 1		77,430			19		(8	)		77,441
	Securities of government-sponsored entities			Less than 1		7,500			—		—			7,500
	Total short-term available-for-sale securities				$	100,945		$	20	$	(15	)	$	100,950
	-1	Unrealized gains and losses are included in other comprehensive income.
	The following table presents certain information related to sales and maturities of available-for-sale investments (in thousands):
			Year Ended December 31,
			2014		2013			2012
	Proceeds from sales/maturities of available-for-sale securities		$	154,133	$	151,283		$	132,520
	Gross realized gains on sales of available-for-sale securities			—		2			—
	Gross realized losses on sales of available-for-sale securities			—		—			—
	Gains reclassified out of accumulated other comprehensive (loss) income into earnings			—		—			—
	The following table presents information about available-for-sale investments in an unrealized loss position (in thousands):
			Less Than 12 Months					12 Months or Greater					Total
			Estimated		Unrealized			Estimated		Unrealized			Estimated		Unrealized
			Fair Value		Losses			Fair Value		Losses			Fair Value		Losses
	December 31, 2014:
	Certificates of deposit		$	16,957	$	(34	)	$	—	$	—		$	16,957	$	(34	)
	Corporate debt securities			149,477		(248	)		—		—			149,477		(248	)
	Securities of government-sponsored entities			1,028		(1	)		—		—			1,028		(1	)
	Total		$	167,462	$	(283	)	$	—	$	—		$	167,462	$	(283	)
	December 31, 2013:
	Certificates of deposit		$	9,802	$	(7	)	$	—	$	—		$	9,802	$	(7	)
	Corporate debt securities			29,919		(8	)		—		—			29,919		(8	)
	Total		$	39,721	$	(15	)	$	—	$	—		$	39,721	$	(15	)

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	NOTE 4. FAIR VALUE MEASUREMENTS
	Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:
	Level 1:	Observable inputs such as quoted prices in active markets;
	Level 2:	Inputs include quoted prices for similar instruments in active markets and/or quoted prices for identical or similar instruments in markets that are not active near the measurement date; and
	Level 3:	Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.
	The Company classifies its cash equivalents and available for sale investments within Level 1 or Level 2. The fair value of the Company’s high quality investment grade corporate debt securities is determined using proprietary valuation models and analytical tools. These valuation models and analytical tools use market pricing or prices for similar instruments that are both objective and publicly available, including matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids and/or offers. The Company did not reclassify any investments between levels in the fair value hierarchy during the years ended December 31, 2014 and 2013.
	The Company’s assets which are measured at fair value on a recurring basis as of December 31, 2014 and 2013 were determined using the inputs described above (in millions):
					Fair Value Measurements Using
		Carrying			Quoted Prices in			Significant Other			Significant
		Value			Active Markets for			Observable			Unobservable Inputs
					Identical Assets			Inputs			(Level 3)
					(Level 1)			(Level 2)
	December 31, 2014:
	Classified as current assets:
	Cash and money market funds	$	28.7		$	28.7		$	—		$	—
	Certificates of deposit		9.1			9.1			—			—
	Commercial paper		7.5			—			7.5			—
	Securities of government-sponsored entities		1.5			—			1.5			—
	Corporate debt securities		147			—			147			—
	Subtotal		193.8			37.8			156			—
	Classified as long-term assets:
	Certificates of deposit		13.2			13.2			—			—
	Corporate debt securities		29.1			—			29.1			—
	Total		236.1			51			185.1			—
	Less cash, cash equivalents and restricted cash		(35.8	)		(33.5	)		(2.3	)		—
	Total investments	$	200.3		$	17.5		$	182.8		$	—
	December 31, 2013:
	Classified as current assets:
	Cash and money market funds	$	34.9		$	34.9		$	—		$	—
	Certificates of deposit		11			11			—			—
	Commercial paper		5			—			5			—
	Securities of government-sponsored entities		7.5			—			7.5			—
	Corporate debt securities		87.4			—			87.4			—
	Subtotal		145.8			45.9			99.9			—
	Classified as long-term assets:
	Certificates of deposit		4.4			4.4			—			—
	Total		150.2			50.3			99.9			—
	Less cash, cash equivalents and restricted cash		(49.2	)		(39.3	)		(9.9	)		—
	Total investments	$	101		$	11		$	90		$	—

PROPERTY_AND_EQUIPMENT

PROPERTY AND EQUIPMENT	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	NOTE 5. PROPERTY AND EQUIPMENT
	Property and equipment, net, at December 31, 2014 and 2013 consisted of the following (in thousands):
		2014			2013
	Tenant improvements		1,226			1,195
	Furniture and fixtures		819			819
	Equipment		29,208			28,089
			31,253			30,103
	Less accumulated depreciation		(28,746	)		(28,332	)
	Property and equipment, net	$	2,507		$	1,771
	For each of the years ended December 31, 2014, 2013 and 2012, depreciation expense was $0.8 million, $0.7 million and $0.7 million, respectively. During 2014, 2013 and 2012, the Company recognized a (loss) gain of approximately ($4,000), $37,000 and $32,000, respectively, related to disposal of capital equipment.

ACCRUED_LIABILITIES

ACCRUED LIABILITIES	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
ACCRUED LIABILITIES	NOTE 6. ACCRUED LIABILITIES
	Accrued liabilities at December 31, 2014 and 2013 consisted of the following (in thousands):
		2014		2013
	Accrued employee related costs	$	6,520	$	3,403
	Accrued development costs		1,706		1,387
	Other accrued liabilities		3,282		3,165
		$	11,508	$	7,955

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	NOTE 7. COMMITMENTS AND CONTINGENCIES
	Real Estate. In December 2007, the Company closed the sale of its facility and associated real property for a purchase price of $109 million. Concurrent with the sale, the Company retired the entire $47.7 million in mortgage debt previously outstanding with respect to the facility and associated real property, and received cash of $61.0 million net of transaction costs and debt retirement.
	Upon the closing of the sale of the facility and associated real property, the Company entered into a lease agreement (Lease) with DMH Campus Investors, LLC (DMH) whereby it leased back for an initial term of 12 years its corporate headquarters comprised of two buildings located at 12790 El Camino Real (Front Building) and 12780 El Camino Real (Rear Building) in San Diego, California. The Company also entered into a series of lease amendments (Amendments), beginning in late 2008, through which it vacated the Front Building, but continues to occupy the Rear Building. The ultimate result of this real estate sale was a net gain of $39.1 million which was deferred in accordance with authoritative guidance. For the years ended December 31, 2014, 2013 and 2012, the Company recognized $3.2 million, $3.1 million and $3.0 million, respectively, of the deferred gain and will recognize the remaining $17.6 million of the deferred gain over the initial Lease term which will expire at the end of 2019.
	Under the terms of the Lease and the Amendments, the Company pays base annual rent (subject to an annual fixed percentage increase), plus a 3.5% annual management fee, property taxes and other normal and necessary expenses associated with the Lease such as utilities, repairs and maintenance. In lieu of a cash security deposit under the Lease, Wells Fargo Bank, N.A. issued on the Company’s behalf a letter of credit in the amount of $4.6 million, which is secured by a deposit of equal amount with the same bank. The Company also has the right to extend the Lease for two consecutive ten-year terms.
	In December 2010, the Company entered into a sublease agreement (Sublease) for approximately 16,000 square feet of the Rear Building. The Sublease is expected to result in approximately $0.6 million of rental income per year over the three year term of the Sublease and is recorded as an offset to rent expense. The Sublease provides an option to extend for two one-year renewal periods. The income generated under the Sublease is lower than the Company’s financial obligation under the Lease for the Rear Building with DMH, as determined on a per square foot basis. Consequently, at December 31, 2010 the Company was required to record a cease-use liability for the net present value estimated difference between the expected income to be generated under the Sublease and future subleases and the Lease obligation over the remaining term of the Lease for the space that is occupied by the subtenant. This transaction resulted in $2.5 million of gross cease-use expense, and a reversal of $173,000 in associated deferred rent, being recorded in December 2010. In August 2012, the Company extended the terms of the Sublease and increased the leased square footage to approximately 17,000 square feet. This transaction resulted in approximately $150,000 of gross cease-use expense, and a reversal of $15,000 in associated deferred rent, being recorded in September 2012.
	In September 2011, the Company entered into a second sublease agreement (Second Sublease) for approximately 3,300 square feet of space in the Rear Building. The Second Sublease is expected to result in approximately $0.1 million in rental income per year over the three year term and is recorded as an offset to rent expense. The Second Sublease provides an option to extend for a one-year renewal period which was exercised in 2013. Similar to the Sublease, the Second Sublease resulted in $0.3 million of gross cease-use expense, and a reversal of $47,000 in associated deferred rent, being recorded in September 2011.
	In November 2012, the Company entered into a third sublease agreement (Third Sublease) for approximately 14,000 square feet of space in the Rear Building. The Third Sublease is expected to result in approximately $0.5 million in rental income per year over the three and a half year term and is recorded as an offset to rent expense. The Third Sublease provides the subtenant with an option to extend the term for two one-year renewal periods. Similar to the previous subleases, the Third Sublease resulted in $1.2 million of gross cease-use expense, and a reversal of $250,000 in associated deferred rent, being recorded in December 2012.
	The following table sets forth changes to the accrued cease-use liability during 2014 and 2013 (in thousands):
		Years Ended
		December 31,
		2014			2013
	Beginning balance	$	3,096		$	3,686
	Payments		(418	)		(590	)
	Ending balance	$	2,678		$	3,096
	Rent Expense. Rent expense was $5.9 million for each of the years ended December 31, 2014, 2013 and 2012, respectively. For financial reporting purposes, the Company recognizes rent expense on a straight-line basis over the term of the lease. Accordingly, rent expense recognized in excess of rent paid is reflected as a liability in the accompanying consolidated balance sheets.
	Lease Commitments. The Company leases its office and research laboratories under an operating lease with an initial term of twelve years, expiring at the end of 2019. Additionally, the Company’s facility lease agreement calls for it to maintain $50 million in cash and investments at all times, or to increase the security deposit by $5 million.
	As of December 31, 2014, the total estimated future annual minimum lease payments under the Company’s non-cancelable building lease for the years ending after December 31, 2014 were as follows (in thousands):
		Payment Amount
	2015	$	7,385
	2016		7,606
	2017		7,834
	2018		8,070
	2019		8,311
	Thereafter		—
	Total future minimum lease payments	$	39,206
	Product Liability. The Company’s business exposes it to liability risks from its potential drug products. A successful product liability claim or series of claims brought against the Company could result in payment of significant amounts of money and divert management’s attention from running the business. The Company may not be able to maintain insurance on acceptable terms, or the insurance may not provide adequate protection in the case of a product liability claim. To the extent that product liability insurance, if available, does not cover potential claims, the Company would be required to self-insure the risks associated with such claims. The Company believes that it carries reasonably adequate insurance for product liability claims.
	Licensing and Research Agreements. The Company has entered into inlicensing agreements with various universities and research organizations, which are generally cancelable at the option of the Company with terms ranging from 0-180 days written notice. Under the terms of these agreements, the Company has received licenses to research tools, know-how and technology claimed, in certain patents or patent applications. The Company is required to pay fees, milestones and/or royalties on future sales of products employing the technology or falling under claims of a patent, and some of the agreements require minimum royalty payments. Some of the agreements also require the Company to pay expenses arising from the prosecution and maintenance of the patents covering the inlicensed technology. The Company continually reassesses the value of the license agreements and cancels them when research efforts are discontinued on these programs. If all inlicensed and research candidates are successfully developed, the Company may be required to pay milestone payments of approximately $17 million over the lives of these agreements, in addition to royalties on sales of the affected products at rates ranging up to 5%. Due to the uncertainties of the development process, the timing and probability of the milestone and royalty payments cannot be accurately estimated.
	Litigation. From time to time, the Company may be subject to legal proceedings and claims in the ordinary course of business. The Company is not aware of any such proceedings or claims that it believes will have, individually or in the aggregate, a material adverse effect on its business, financial condition or results of operations.

SHAREBASED_COMPENSATION

SHARE-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
SHARE-BASED COMPENSATION	NOTE 8. SHARE-BASED COMPENSATION
	Share-Based Compensation Plans. In May 2011, the Company adopted the Neurocrine Biosciences, Inc. 2011 Equity Incentive Plan (the 2011 Plan) pursuant to which 8.5 million shares of Company common stock are authorized for issuance. The 2011 Plan provides for the grant of stock options that qualify as incentive stock options under Section 422 of the Internal Revenue Code of 1986, as amended (the Code), nonstatutory stock options, restricted stock awards, restricted stock unit awards (RSUs), stock appreciation rights, performance stock awards, performance-based restricted stock units (PRSUs) and other forms of equity compensation.
	The Company also issues stock options under the Neurocrine Biosciences, Inc. Inducement Plan to certain executive level employees. During 2014, 160,000 stock options were granted pursuant to such inducement plan. These stock option grants have a four year vesting period. The Company currently has approximately 0.2 million in stock options outstanding under such inducement plans.
	As of December 31, 2014, approximately 2.7 million remained available for future grant awards under the 2011 Plan. Only share awards made under the 2011 Plan that are subsequently cancelled due to forfeiture or expiration are returned to the share pool available for future grants.
	The Company issues new shares upon the exercise of stock options, the issuance of stock bonus awards and vesting of RSUs and PRSUs, and has 9.5 million shares of common stock reserved for such issuance as of December 31, 2014.
	Vesting Provisions of Share-Based Compensation. Stock options generally have terms from seven to ten years from the date of grant, and generally vest over a three to four-year period. The maximum contractual term for all options granted from the 2011 Plan is ten years. RSUs granted under the 2011 Plan generally have vesting periods of four years. PRSUs granted under the 2011 Plan vest based on the achievement of certain pre-defined Company-specific performance criteria and expire five years from the grant date.
	Share-Based Compensation. The compensation cost that has been included in the statement of comprehensive (loss) income for all share-based compensation arrangements is as follows (in thousands):
		Years Ended December 31,
		2014			2013			2012
	General and administrative expense	$	5,167		$	3,516		$	2,746
	Research and development expense		5,215			3,303			2,733
	Share-based compensation expense	$	10,382		$	6,819		$	5,479
	Authoritative guidance requires that cash flows resulting from tax deductions in excess of the cumulative compensation cost recognized for options exercised be classified as cash inflows provided by financing activities and cash outflows used in operating activities. Due to the Company’s net tax loss position, no tax benefits have been recognized in the consolidated statements of cash flows.
	Stock Options. The exercise price of all options granted during the years ended December 31, 2014, 2013 and 2012 was equal to the closing price of the Company’s common stock on the date of grant. The estimated fair value of each option award granted was determined on the date of grant using the Black-Scholes option-pricing valuation model with the following weighted-average assumptions for option grants during the three years ended December 31, 2014:
		Years Ended December 31,
		2014			2013			2012
	Risk-free interest rate		2.2	%		1.4	%		1.3	%
	Expected volatility of common stock		71	%		76	%		79	%
	Dividend yield		0	%		0	%		0	%
	Expected option term		7.2 years			7.3 years			6.8 years
	The Company estimates the fair value of stock options using a Black-Scholes option-pricing model on the date of grant. The fair value of equity instruments that are ultimately expected to vest, net of estimated forfeitures, are recognized and amortized on a straight-line basis over the requisite service period. The Black-Scholes option-pricing model incorporates various and highly sensitive assumptions including expected volatility, expected term and interest rates. The expected volatility is based on the historical volatility of the Company’s common stock over the most recent period commensurate with the estimated expected term of the Company’s stock options. The expected option term is estimated based on historical experience as well as the status of the employee. For example, directors and officers have a longer expected option term than all other employees. Additionally, grants of stock options during the past three years have a contractual life of ten years, versus seven years for older option grants, and the vesting period for these same option grants has been extended to four years, which together have resulted in an increase in the expected option term. The risk-free rate for periods within the contractual life of the option is based upon observed interest rates appropriate for the expected term of the Company’s employee stock options. The Company has never declared or paid dividends and has no plans to do so in the foreseeable future.
	Authoritative guidance requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Pre-vesting forfeitures for awards with monthly vesting terms were estimated to be 0% in 2014 based on historical experience. Pre-vesting forfeitures for awards with annual vesting terms were also estimated at 0% in 2014 based on historical employee turnover experience. The effect of past restructurings has been excluded from the historical review of employee turnover. The effect of pre-vesting forfeitures for awards has historically been negligible on the Company’s recorded expense. The Company’s determination of fair value is affected by the Company’s stock price as well as a number of assumptions that require judgment. The weighted-average fair values of options granted during the years ended December 31, 2014, 2013 and 2012, estimated as of the grant date using the Black-Scholes option valuation model, were $12.57, $6.55 and $6.05, respectively.
	A summary of the status of the Company’s stock options as of December 31, 2014, 2013 and 2012 and of changes in options outstanding under the plans during the three years ended December 31, 2014 is as follows (in thousands, except for weighted average exercise price data):
		2014						2013					2012
		Options			Weighted			Options			Weighted		Options			Weighted
					Average						Average					Average
					Exercise Price						Exercise Price					Exercise Price
	Outstanding at January 1		5,853		$	7.54			6,166		$	7.62		5,315		$	8.82
	Granted/amended		1,089			18.41			771			9.24		1,446			8.5
	Exercised		(1,135	)		6.5			(904	)		5.96		(209	)		3.49
	Canceled		(57	)		56.83			(180	)		25.68		(386	)		29.66
	Outstanding at December 31		5,750		$	9.31			5,853		$	7.54		6,166		$	7.62
	Options outstanding at December 31, 2014 have a weighted average remaining contractual term of 6.4 years.
	For the year ended December 31, 2014, share-based compensation expense related to stock options was $7.8 million. As of December 31, 2014, there was approximately $14.7 million of unamortized compensation cost related to stock options, which is expected to be recognized over a weighted average remaining vesting period of approximately 2.7 years. As of December 31, 2014, there were approximately 4.2 million options exercisable with a weighted average exercise price of $7.55 and a weighted-average remaining contractual term of 5.6 years. The total intrinsic value, which is the amount by which the exercise price was exceeded by the sale price of the Company’s common stock on the date of sale, of stock option exercises during the years ended December 31, 2014, 2013, and 2012 was $14.3 million, $6.0 million and $943,000, respectively. As of December 31, 2014, the total intrinsic value of options outstanding and exercisable was $77.1 million and $64.3 million, respectively. Cash received from stock option exercises for the years ended December 31, 2014, 2013 and 2012 was $5.6 million, $5.3 million and $0.7 million, respectively.
	Restricted Stock Units. Certain employees receive RSUs under the 2011 Plan. The fair value of RSUs is based on the closing sale price of the Company’s common stock on the date of issuance. The total number of RSUs expected to vest is adjusted by estimated forfeiture rates, which has been based on historical experience of equity awards and historical employee turnover experience. The effect of pre-vesting forfeitures for awards has historically been negligible on the Company’s recorded expense and was estimated at 0% in 2014. The effect of past restructurings has been excluded from the historical review of employee turnover. For the year ended December 31, 2014, 2013 and 2012, share-based compensation expense related to RSUs was $2.6 million, $0.8 million, and $0, respectively. As of December 31, 2014, there was approximately $7.5 million of unamortized compensation cost related to RSUs, which is expected to be recognized over a weighted average remaining vesting period of approximately 2.9 years.
	The total intrinsic value of RSUs converted into common shares during the years ended December 31, 2014, 2013 and 2012 was $1.7 million, $0, and $0.4 million, respectively. The RSUs, at the election of eligible employees, may be subject to deferred delivery arrangement. The total intrinsic value of RSUs outstanding at December 31, 2014 was $15.0 million based on the Company’s closing stock price on that date.
	A summary of the status of the Company’s RSUs as of December 31, 2014, 2013 and 2012 and of changes in RSUs outstanding under the plans for the three years ended December 31, 2014 is as follows (in thousands, except for weighted average grant date fair value per unit):
		2014						2013					2012
		Number of			Weighted Average			Number of			Weighted Average		Number of			Weighted Average
		Units			Grant Date Fair			Units			Grant Date Fair		Units			Grant Date Fair
					Value per Unit						Value per Unit					Value per Unit
	Restricted stock units outstanding at January 1		373		$	8.65			—		$	—		50		$	5.88
	Restricted stock units granted		389			19.59			379			8.65		—			—
	Restricted stock units cancelled		—			—			(6	)		8.65		—			—
	Restricted stock units converted into common shares		(93	)		8.65			—			—		(50	)		5.88
	Restricted stock units outstanding at December 31		669		$	15.01			373		$	8.65		—		$	—
	Performance-Based Restricted Stock Units. During the year ended December 31, 2014, the Company granted approximately 0.5 million PRSUs that vest based on the achievement of certain pre-defined Company-specific performance criteria and expire five years from the grant date. As the performance based criteria for vesting for the PRSUs is not currently probable, no associated expense has been recorded for the PRSUs during the year ended December 31, 2014. The total unrecognized estimated compensation expense related to these PRSUs is $9.3 million and is expected to be recognized when the performance condition have been achieved, which is when these events will become probable. The total intrinsic value of PRSUs outstanding at December 31, 2014 was $10.6 million based on the Company’s closing stock price on that date.

STOCKHOLDERS_EQUITY

STOCKHOLDERS' EQUITY	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
STOCKHOLDERS' EQUITY	NOTE 9. STOCKHOLDERS’ EQUITY
	Equity Financing
	In February 2014, the Company completed a public offering of common stock in which the Company sold 8.0 million shares of our common stock at an offering price of $17.75 per share. The shares were sold pursuant to an automatic shelf registration statement filed with the Securities and Exchange Commission (SEC). The net proceeds generated from this transaction, after underwriting discounts and commissions and offering costs, were approximately $133.2 million.
	In January 2012, the Company completed a public offering of common stock in which the Company sold 10.9 million shares of its common stock at an offering price of $8.10 per share. The shares were sold pursuant to a shelf registration statement previously on file with the SEC. The net proceeds generated from this transaction, after underwriting discounts and commissions and offering costs, were approximately $83.0 million.
	Shelf Registration Statement
	In February 2014, the Company filed an automatic shelf registration statement which immediately became effective by rule of the SEC. For so long as the Company continues to satisfy the requirements to be deemed a well-known seasoned issuer, this shelf registration statement allows the Company to issue an unlimited number of shares of its common stock from time to time. As of December 31, 2014, the Company had sold 8.0 million shares under this shelf registration statement.
	In December 2012, the SEC declared effective a shelf registration statement filed by the Company in November 2012. The shelf registration statement allows the Company to issue shares of its common stock from time to time for an aggregate initial offering price of up to $150 million. The specific terms of future offerings, if any, under the shelf registration statement would be established at the time of such offerings.

INCOME_TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
INCOME TAXES	NOTE 10. INCOME TAXES
	Under the FASB’s accounting guidance related to uncertain tax positions, among other things, the impact of an uncertain income tax position on the income tax return must be recognized at the largest amount that is more-likely-than-not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. Additionally, the guidance provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition.
	The Company’s policy is to recognize interest and/or penalties related to income tax matters in income tax expense. The Company had no accrual for interest or penalties on the Company’s consolidated balance sheets at December 31, 2014 or December 31, 2013, and has not recognized interest and/or penalties in the statement of comprehensive (loss) income for the year ended December 31, 2014.
	The Company is subject to taxation in the United States and various state jurisdictions. The Company’s tax years for 1998 (federal)/1997 (California) and forward are subject to examination by the United States and California tax authorities due to the carry forward of unutilized net operating losses and R&D credits.
	At December 31, 2014, the Company had deferred tax assets of $367.1 million. Due to uncertainties surrounding the Company’s ability to generate future taxable income to realize these assets, a full valuation has been established to offset the net deferred tax asset. Additionally, the future utilization of the Company’s net operating loss and research and development credit carry forwards to offset future taxable income may be subject to an annual limitation, pursuant to Internal Revenue Code Sections 382 and 383, as a result of ownership changes that could occur in the future. The Company has determined that no ownership changes have occurred through December 31, 2014.
	At December 31, 2014, the Company had Federal and California income tax net operating loss carry forwards of approximately $668.3 million and $652.8 million, respectively. The Federal tax loss carry forwards will begin to expire in 2021, unless previously utilized.
	The California net operating loss carry forwards will expire as follows (in thousands):
	Year	Amount
	2015	68,500
	2016	113,400
	2017	72,100
	2018	140,600
	2028 and beyond	258,200
	In addition, the Company has Federal and California R&D tax credit carry forwards of $33.9 million and $23.6 million, respectively. The Federal research and development tax credit carry forwards begin expiring in 2018 and will continue to expire unless utilized. The California research and development tax credit carryforwards carry forward indefinitely. The Company also has Federal Alternative Minimum Tax credit carryforwards of approximately $227,000, which will carry forward indefinitely. At December 31, 2014, approximately $26.5 million of the net operating loss carry forwards relate to stock option exercises, which will result in an increase to additional paid-in capital and a decrease in income taxes payable at the time when the tax loss carryforwards are utilized.
	Significant components of the Company’s deferred tax assets as of December 31, 2014 and 2013 are listed below. A valuation allowance of $367.1 million and $341.7 million at December 31, 2014 and 2013, respectively, has been recognized to offset the deferred tax assets as realization of such assets is uncertain. Amounts are shown as of December 31 as of each respective year (in thousands):
		2014			2013
	Deferred tax assets:
	Net operating losses	$	260,600		$	246,500
	Research and development credits		29,000			27,700
	Capitalized research and development		45,700			34,500
	Share-based compensation expense		6,900			5,200
	Deferred revenue		800			800
	Deferred gain on sales leaseback		7,200			8,500
	Intangibles		10,600			13,200
	Cease-use expense		1,100			1,300
	Fixed assets		500			300
	Other		4,700			3,700
	Total deferred tax assets		367,100			341,700
	Valuation allowance		(367,100	)		(341,700	)
	Net deferred tax assets	$	—		$	—
	The provision for income taxes on earnings subject to income taxes differs from the statutory Federal rate at December 31, 2014, 2013 and 2012, due to the following (in thousands):
		2014			2013			2012
	Federal income taxes at 35%	$	(21,190	)	$	(16,131	)	$	1,759
	State income tax, net of Federal benefit		(3,410	)		(2,611	)		406
	Tax effect on non-deductible expenses		10			7			9
	Share-based compensation expense		91			215			1,154
	Expired tax attributes		315			151			327
	Research credits		(1,882	)		(3,458	)		(428	)
	Change in valuation allowance		25,366			20,504			(4,061	)
	Uncertain tax positions		621			1,283			876
	Other		79			40			(42	)
		$	—		$	—		$	—
	The following table summarizes the activity related to our unrecognized tax benefits (in thousands):
		2014			2013			2012
	Balance as of the beginning of the year	$	23,131		$	21,672		$	20,237
	Increases related to prior year tax positions		47			543			1,434
	Increases related to current year tax positions		676			916			165
	Expiration of the statute of limitations for the assessment of taxes		—			—			(164	)
	Balance as of the end of the year	$	23,854		$	23,131		$	21,672
	The Company, under authoritative guidance, excluded those deferred tax assets that are not more likely than not to be sustained under the technical merits of the tax position. These unrecognized tax benefits totaled $47,000 and $0.7 million for prior year tax positions and current year tax positions, respectively, as reflected in the tabular rollforward above.
	As of December 31, 2014, the Company had $20.2 million of unrecognized tax benefits that, if recognized and realized, would effect the effective tax rate.
	In the next twelve months, the Company does not expect a significant change in their unrecognized tax benefits.

RETIREMENT_PLAN

RETIREMENT PLAN	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
RETIREMENT PLAN	NOTE 11. RETIREMENT PLAN
	The Company has a 401(k) defined contribution savings plan (401(k) Plan). The 401(k) Plan is for the benefit of all qualifying employees and permits voluntary contributions by employees up to 60% of base salary limited by the IRS-imposed maximum. Employer contributions were $0.3 million, $0.3 million and $0.2 million for the years ended December 31, 2014, 2013 and 2012, respectively.

SUBSEQUENT_EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	NOTE 12. SUBSEQUENT EVENTS
	The Company evaluated all subsequent events that have occurred after the date of the accompanying financial statements and determined that there were no events or transactions occurring during this subsequent event reporting period which require recognition or disclosure in the Company’s financial statements, other than as disclosed below.

SELECTED_QUARTERLY_FINANCIAL_D

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	NOTE 13. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)
	The following is a summary of the quarterly results of the Company for the years ended December 31, 2014 and 2013 (unaudited, in thousands, except for per share data):
		Year Ended December 31,												Year Ended
		First			Second			Third			Fourth			December 31
		Quarter			Quarter			Quarter			Quarter
	2014:00:00
	Revenues	$	—		$	—		$	—		$	—		$	—
	Operating expenses		12,725			14,361			16,857			20,468			64,411
	Net loss		(11,842	)		(13,381	)		(15,875	)		(19,444	)		(60,542	)
	Net loss per share:
	Basic and Diluted	$	(0.17	)	$	(0.18	)	$	(0.21	)	$	(0.26	)	$	(0.81	)
	Shares used in the calculation of net loss per share:
	Basic and Diluted		70,260			75,879			75,948			76,139			74,577
	2013:00:00
	Revenues	$	730		$	730		$	729		$	730		$	2,919
	Operating expenses		13,705			13,897			12,735			12,260			52,597
	Net loss		(12,075	)		(12,242	)		(11,131	)		(10,642	)		(46,090	)
	Net loss per share:
	Basic and Diluted	$	(0.18	)	$	(0.18	)	$	(0.17	)	$	(0.16	)	$	(0.69	)
	Shares used in the calculation of net loss per share:
	Basic and Diluted		66,600			66,799			67,199			67,346			66,989

ORGANIZATION_AND_SUMMARY_OF_SI1

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation. The consolidated financial statements include the accounts of Neurocrine as well as its wholly owned subsidiaries. The Company does not have any significant interests in any variable interest entities. All intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the financial statements and the accompanying notes. Actual results could differ from those estimates.
Cash Equivalents	Cash Equivalents. The Company considers all highly liquid investments that are readily convertible into cash and have an original maturity of three months or less at the time of purchase to be cash equivalents.
Short-Term and Long-Term Investments Available-for-Sale	Short-Term and Long-Term Investments Available-for-Sale. Certain investments are classified as available-for-sale and, in accordance with authoritative guidance, are carried at fair value, with the unrealized gains and losses reported in other comprehensive (loss) income. The amortized cost of debt securities in this category is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included in investment income. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on available-for-sale securities are included in other income or expense. The cost of securities sold is based on the specific identification method. Interest and dividends on securities classified as available-for-sale are included in investment income.
Concentration of Credit Risk	Concentration of Credit Risk. Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents and investments. The Company has established guidelines to limit its exposure to credit risk by placing investments with high credit quality financial institutions, diversifying its investment portfolio and placing investments with maturities that maintain safety and liquidity.
Collaboration Agreements	Collaboration Agreements. During the years ended December 31, 2013 and 2012 collaborative R&D agreements accounted for all of the Company’s revenue.
Property and Equipment	Property and Equipment. Property and equipment are stated at cost and depreciated over the estimated useful lives of the assets using the straight-line method. Equipment is depreciated over an average estimated useful life of three to seven years. Leasehold improvements are depreciated over the shorter of their estimated useful lives or the remaining lease term.
Industry Segment and Geographic Information	Industry Segment and Geographic Information. The Company operates in a single industry segment – the discovery and development of therapeutics for the treatment of neurological and endocrine based diseases and disorders. The Company had no foreign based operations during any of the years presented.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets. The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. If indicators of impairment exist, the Company assesses the recoverability of the affected long-lived assets by determining whether the carrying value of such assets can be recovered through undiscounted future operating cash flows. If the carrying amount is not recoverable, the Company measures the amount of any impairment by comparing the carrying value of the asset to the present value of the expected future cash flows associated with the use of the asset.
Fair Value of Financial Instruments	Fair Value of Financial Instruments. Financial instruments, including cash and cash equivalents, accounts receivable, accounts payable, and accrued liabilities, are carried at cost, which management believes approximates fair value because of the short-term maturity of these instruments.
	Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:
	Level 1:	Observable inputs such as quoted prices in active markets;
	Level 2:	Inputs include quoted prices for similar instruments in active markets and/or quoted prices for identical or similar instruments in markets that are not active near the measurement date; and
	Level 3:	Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.
	The Company classifies its cash equivalents and available for sale investments within Level 1 or Level 2. The fair value of the Company’s high quality investment grade corporate debt securities is determined using proprietary valuation models and analytical tools. These valuation models and analytical tools use market pricing or prices for similar instruments that are both objective and publicly available, including matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids and/or offers.
Research and Development Expenses	Research and Development Expenses. R&D expenses consists primarily of salaries, payroll taxes, employee benefits, and share-based compensation charges, for those individuals involved in ongoing R&D efforts; as well as scientific contractor fees, preclinical and clinical trial costs, R&D facilities costs, laboratory supply costs, and depreciation of scientific equipment. All such costs are charged to R&D expense as incurred. These expenses result from the Company’s independent R&D efforts as well as efforts associated with collaborations and in-licensing arrangements. In addition, the Company funds R&D at other companies and research institutions under agreements, which are generally cancelable. The Company reviews and accrues clinical trial expenses based on work performed, which relies on estimates of total costs incurred based on patient enrollment, completion of patient studies and other events. The Company follows this method since reasonably dependable estimates of the costs applicable to various stages of a research agreement or clinical trial can be made. Accrued clinical costs are subject to revisions as trials progress. Revisions are charged to expense in the period in which the facts that give rise to the revision become known.
Share-Based Compensation	Share-Based Compensation. The Company estimates the fair value of stock options using the Black-Scholes option pricing model on the date of grant. Restricted stock units are valued based on the closing price of the Company’s common stock on the date of grant. The fair value of equity instruments expected to vest are recognized and amortized on a straight-line basis over the requisite service period of the award, which is generally three to four years; however, certain provisions in the Company’s equity compensation plans provide for shorter vesting periods under certain circumstances. Additionally, the Company has granted certain performance-based equity awards that vest upon the achievement of certain pre-defined Company-specific performance criteria. Expense related to these performance-based equity awards is generally recognized upon achievement of the specific performance criteria.
Investment Income, net	Investment Income, net. Investment income, net is comprised of interest and dividends earned on cash, cash equivalents and investments as well as gains and losses realized from activity in the Company’s investment portfolio. Available-for-sale securities are carried at fair value, with the unrealized gains and losses reported in comprehensive (loss) income. The amortized cost of debt securities in this category is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included in investment income. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on available-for-sale securities are included in other income or expense. The cost of securities sold is based on the specific identification method. Interest and dividends on securities classified as available-for-sale are included in investment income.
Net (Loss) Income Per Share	Net (Loss) Income Per Share. The Company computes basic net (loss) income per share using the weighted average number of common shares outstanding during the period. Diluted net income per share is based upon the weighted average number of common shares and potentially dilutive securities (common share equivalents) outstanding during the period. Common share equivalents outstanding, determined using the treasury stock method, are comprised of shares that may be issued under the Company’s stock option agreements. Common share equivalents are excluded from the diluted net loss per share calculation because of their anti-dilutive effect.
	Due to the net loss position in 2014 and 2013, approximately 2.9 million and 2.1 million, respectively, of common share equivalents were excluded from the diluted common shares outstanding. At December 31, 2012, the Company had approximately 1.3 million of additional common share equivalents outstanding that were included in the diluted income per share calculation. For the years ended December 31, 2014, 2013 and 2012, there were employee stock options, calculated on a weighted average basis, to purchase 1.0 million, 0.3 million and 2.2 million shares of our common stock with an exercise price greater than the average market price of the underlying common shares.
Impact of Recently Issued Accounting Standards	Impact of Recently Issued Accounting Standards. In May 2014, the Financial Accounting Standards Board (FASB) amended the existing accounting standards for revenue recognition. The amendments are based on the principle that revenue should be recognized to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for said goods or services. The Company is required to adopt the amendments beginning in 2017. Early adoption is not permitted. The amendments may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized as of the date of initial application. The Company is currently evaluating the impact that these amendments will have on its consolidated financial statements.
	In July 2013, the FASB issued guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013, with an option for early adoption. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements.
Revenue Recognition Policy	Revenue Recognition Policy. Revenues under collaborative agreements and grants are recognized as research costs are incurred over the period specified in the related agreement or as the services are performed. These agreements are on a best-efforts basis, do not require scientific achievement as a performance obligation and provide for payment to be made when costs are incurred or the services are performed. All fees are nonrefundable to the collaborators. Prior to the revised multiple element guidance adopted by the Company on January 1, 2011, upfront, nonrefundable payments for license fees, grants, and advance payments for sponsored research revenues received in excess of amounts earned were classified as deferred revenue and recognized as income over the contract or development period. Estimating the duration of the development period includes continual assessment of development stages and regulatory requirements. If and when the Company enters into a new collaboration agreement or materially modifies an existing collaboration agreement, the Company will be required to apply the new multiple element guidance. Milestone payments are recognized as revenue upon achievement of pre-defined scientific events, which require substantive effort, and for which achievement of the milestone was not readily assured at the inception of the agreement.

ORGANIZATION_AND_SUMMARY_OF_SI2

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Components of Investment Income	The following table presents certain information related to the components of investment income (in thousands):
		Years Ended December 31,
		2014		2013		2012
	Interest income		629		400		489
	Realized gains, net		—		2		—
	Total	$	629	$	402	$	489

INVESTMENTS_Tables

INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Investments Schedule [Abstract]
Investments	Investments at December 31, 2014 and 2013 consisted of the following (in thousands):
			Years Ended
			December 31,
			2014		2013
	Certificates of deposit		$	17,438	$	11,012
	Commercial paper			7,498		4,997
	Corporate debt securities			174,323		77,441
	Securities of government-sponsored entities			1,028		7,500
	Total investments		$	200,287	$	100,950
Summary of Investments Classified as Available-For-Sale Securities	The following is a summary of investments classified as available-for-sale securities (in thousands):
			Contractual		Amortized			Gross		Gross			Aggregate
			Maturity		Cost			Unrealized		Unrealized			Estimated
			(in years)					Gains(1)		Losses(1)			Fair
													Value
	December 31, 2014:
	Classified as current assets:
	Certificates of deposit			Less than 1	$	9,072		$	—	$	(6	)	$	9,066
	Commercial paper			Less than 1		7,497			1		—			7,498
	Corporate debt securities			Less than 1		145,321			5		(123	)		145,203
	Securities of government-sponsored entities			Less than 1		1,029			—		(1	)		1,028
	Total short-term available-for-sale securities				$	162,919		$	6	$	(130	)	$	162,795
	Classified as non-current assets:
	Certificates of deposit			1 to 2	$	8,400		$	—	$	(28	)	$	8,372
	Corporate debt securities			1 to 2		29,245			—		(125	)		29,120
	Total long-term available-for-sale securities				$	37,645		$	—	$	(153	)	$	37,492
	December 31, 2013:
	Classified as current assets:
	Certificates of deposit			Less than 1	$	11,018		$	1	$	(7	)	$	11,012
	Commercial paper			Less than 1		4,997			—		—			4,997
	Corporate debt securities			Less than 1		77,430			19		(8	)		77,441
	Securities of government-sponsored entities			Less than 1		7,500			—		—			7,500
	Total short-term available-for-sale securities				$	100,945		$	20	$	(15	)	$	100,950
	-1	Unrealized gains and losses are included in other comprehensive income.
Sales and Maturities of Available-For-Sale Investments	The following table presents certain information related to sales and maturities of available-for-sale investments (in thousands):
			Year Ended December 31,
			2014		2013			2012
	Proceeds from sales/maturities of available-for-sale securities		$	154,133	$	151,283		$	132,520
	Gross realized gains on sales of available-for-sale securities			—		2			—
	Gross realized losses on sales of available-for-sale securities			—		—			—
	Gains reclassified out of accumulated other comprehensive (loss) income into earnings			—		—			—
Available-For-Sale Investments in Unrealized Loss Position	The following table presents information about available-for-sale investments in an unrealized loss position (in thousands):
			Less Than 12 Months					12 Months or Greater					Total
			Estimated		Unrealized			Estimated		Unrealized			Estimated		Unrealized
			Fair Value		Losses			Fair Value		Losses			Fair Value		Losses
	December 31, 2014:
	Certificates of deposit		$	16,957	$	(34	)	$	—	$	—		$	16,957	$	(34	)
	Corporate debt securities			149,477		(248	)		—		—			149,477		(248	)
	Securities of government-sponsored entities			1,028		(1	)		—		—			1,028		(1	)
	Total		$	167,462	$	(283	)	$	—	$	—		$	167,462	$	(283	)
	December 31, 2013:
	Certificates of deposit		$	9,802	$	(7	)	$	—	$	—		$	9,802	$	(7	)
	Corporate debt securities			29,919		(8	)		—		—			29,919		(8	)
	Total		$	39,721	$	(15	)	$	—	$	—		$	39,721	$	(15	)

FAIR_VALUE_MEASUREMENTS_Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Assets Measured at Fair Value on Recurring Basis	The Company’s assets which are measured at fair value on a recurring basis as of December 31, 2014 and 2013 were determined using the inputs described above (in millions):
					Fair Value Measurements Using
		Carrying			Quoted Prices in			Significant Other			Significant
		Value			Active Markets for			Observable			Unobservable Inputs
					Identical Assets			Inputs			(Level 3)
					(Level 1)			(Level 2)
	December 31, 2014:
	Classified as current assets:
	Cash and money market funds	$	28.7		$	28.7		$	—		$	—
	Certificates of deposit		9.1			9.1			—			—
	Commercial paper		7.5			—			7.5			—
	Securities of government-sponsored entities		1.5			—			1.5			—
	Corporate debt securities		147			—			147			—
	Subtotal		193.8			37.8			156			—
	Classified as long-term assets:
	Certificates of deposit		13.2			13.2			—			—
	Corporate debt securities		29.1			—			29.1			—
	Total		236.1			51			185.1			—
	Less cash, cash equivalents and restricted cash		(35.8	)		(33.5	)		(2.3	)		—
	Total investments	$	200.3		$	17.5		$	182.8		$	—
	December 31, 2013:
	Classified as current assets:
	Cash and money market funds	$	34.9		$	34.9		$	—		$	—
	Certificates of deposit		11			11			—			—
	Commercial paper		5			—			5			—
	Securities of government-sponsored entities		7.5			—			7.5			—
	Corporate debt securities		87.4			—			87.4			—
	Subtotal		145.8			45.9			99.9			—
	Classified as long-term assets:
	Certificates of deposit		4.4			4.4			—			—
	Total		150.2			50.3			99.9			—
	Less cash, cash equivalents and restricted cash		(49.2	)		(39.3	)		(9.9	)		—
	Total investments	$	101		$	11		$	90		$	—

PROPERTY_AND_EQUIPMENT_Tables

PROPERTY AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and equipment, net, at December 31, 2014 and 2013 consisted of the following (in thousands):
		2014			2013
	Tenant improvements		1,226			1,195
	Furniture and fixtures		819			819
	Equipment		29,208			28,089
			31,253			30,103
	Less accumulated depreciation		(28,746	)		(28,332	)
	Property and equipment, net	$	2,507		$	1,771

ACCRUED_LIABILITIES_Tables

ACCRUED LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued liabilities at December 31, 2014 and 2013 consisted of the following (in thousands):
		2014		2013
	Accrued employee related costs	$	6,520	$	3,403
	Accrued development costs		1,706		1,387
	Other accrued liabilities		3,282		3,165
		$	11,508	$	7,955

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Changes to Accrued Cease-Use Liability	The following table sets forth changes to the accrued cease-use liability during 2014 and 2013 (in thousands):
		Years Ended
		December 31,
		2014			2013
	Beginning balance	$	3,096		$	3,686
	Payments		(418	)		(590	)
	Ending balance	$	2,678		$	3,096
Estimated Future Annual Minimum Lease Payments	As of December 31, 2014, the total estimated future annual minimum lease payments under the Company’s non-cancelable building lease for the years ending after December 31, 2014 were as follows (in thousands):
		Payment Amount
	2015	$	7,385
	2016		7,606
	2017		7,834
	2018		8,070
	2019		8,311
	Thereafter		—
	Total future minimum lease payments	$	39,206

SHAREBASED_COMPENSATION_Tables

SHARE-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Compensation Expenses Related to Share Based Compensation	The compensation cost that has been included in the statement of comprehensive (loss) income for all share-based compensation arrangements is as follows (in thousands):
		Years Ended December 31,
		2014			2013			2012
	General and administrative expense	$	5,167		$	3,516		$	2,746
	Research and development expense		5,215			3,303			2,733
	Share-based compensation expense	$	10,382		$	6,819		$	5,479
Weighted-Average Assumptions for Stock Option Grants using Black-Scholes Option-Pricing Model	The estimated fair value of each option award granted was determined on the date of grant using the Black-Scholes option-pricing valuation model with the following weighted-average assumptions for option grants during the three years ended December 31, 2014:
		Years Ended December 31,
		2014			2013			2012
	Risk-free interest rate		2.2	%		1.4	%		1.3	%
	Expected volatility of common stock		71	%		76	%		79	%
	Dividend yield		0	%		0	%		0	%
	Expected option term		7.2 years			7.3 years			6.8 years
Summary and Changes in Stock Options Outstanding	A summary of the status of the Company’s stock options as of December 31, 2014, 2013 and 2012 and of changes in options outstanding under the plans during the three years ended December 31, 2014 is as follows (in thousands, except for weighted average exercise price data):
		2014						2013					2012
		Options			Weighted			Options			Weighted		Options			Weighted
					Average						Average					Average
					Exercise Price						Exercise Price					Exercise Price
	Outstanding at January 1		5,853		$	7.54			6,166		$	7.62		5,315		$	8.82
	Granted/amended		1,089			18.41			771			9.24		1,446			8.5
	Exercised		(1,135	)		6.5			(904	)		5.96		(209	)		3.49
	Canceled		(57	)		56.83			(180	)		25.68		(386	)		29.66
	Outstanding at December 31		5,750		$	9.31			5,853		$	7.54		6,166		$	7.62
Summary and Changes in Restricted Stock Units Outstanding	A summary of the status of the Company’s RSUs as of December 31, 2014, 2013 and 2012 and of changes in RSUs outstanding under the plans for the three years ended December 31, 2014 is as follows (in thousands, except for weighted average grant date fair value per unit):
		2014						2013					2012
		Number of			Weighted Average			Number of			Weighted Average		Number of			Weighted Average
		Units			Grant Date Fair			Units			Grant Date Fair		Units			Grant Date Fair
					Value per Unit						Value per Unit					Value per Unit
	Restricted stock units outstanding at January 1		373		$	8.65			—		$	—		50		$	5.88
	Restricted stock units granted		389			19.59			379			8.65		—			—
	Restricted stock units cancelled		—			—			(6	)		8.65		—			—
	Restricted stock units converted into common shares		(93	)		8.65			—			—		(50	)		5.88
	Restricted stock units outstanding at December 31		669		$	15.01			373		$	8.65		—		$	—

INCOME_TAXES_Tables

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Expiration of Net Operating Loss Carry Forwards	The California net operating loss carry forwards will expire as follows (in thousands):
	Year	Amount
	2015	68,500
	2016	113,400
	2017	72,100
	2018	140,600
	2028 and beyond	258,200
Components of Deferred Tax Assets	Amounts are shown as of December 31 as of each respective year (in thousands):
		2014			2013
	Deferred tax assets:
	Net operating losses	$	260,600		$	246,500
	Research and development credits		29,000			27,700
	Capitalized research and development		45,700			34,500
	Share-based compensation expense		6,900			5,200
	Deferred revenue		800			800
	Deferred gain on sales leaseback		7,200			8,500
	Intangibles		10,600			13,200
	Cease-use expense		1,100			1,300
	Fixed assets		500			300
	Other		4,700			3,700
	Total deferred tax assets		367,100			341,700
	Valuation allowance		(367,100	)		(341,700	)
	Net deferred tax assets	$	—		$	—
Provision for Income Taxes on Earnings Subject to Income Taxes Differs from Statutory Federal Rate	The provision for income taxes on earnings subject to income taxes differs from the statutory Federal rate at December 31, 2014, 2013 and 2012, due to the following (in thousands):
		2014			2013			2012
	Federal income taxes at 35%	$	(21,190	)	$	(16,131	)	$	1,759
	State income tax, net of Federal benefit		(3,410	)		(2,611	)		406
	Tax effect on non-deductible expenses		10			7			9
	Share-based compensation expense		91			215			1,154
	Expired tax attributes		315			151			327
	Research credits		(1,882	)		(3,458	)		(428	)
	Change in valuation allowance		25,366			20,504			(4,061	)
	Uncertain tax positions		621			1,283			876
	Other		79			40			(42	)
		$	—		$	—		$	—
Activity Related to Unrecognized Tax Benefits	The following table summarizes the activity related to our unrecognized tax benefits (in thousands):
		2014			2013			2012
	Balance as of the beginning of the year	$	23,131		$	21,672		$	20,237
	Increases related to prior year tax positions		47			543			1,434
	Increases related to current year tax positions		676			916			165
	Expiration of the statute of limitations for the assessment of taxes		—			—			(164	)
	Balance as of the end of the year	$	23,854		$	23,131		$	21,672

SELECTED_QUARTERLY_FINANCIAL_D1

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results of Operations	The following is a summary of the quarterly results of the Company for the years ended December 31, 2014 and 2013 (unaudited, in thousands, except for per share data):
		Year Ended December 31,												Year Ended
		First			Second			Third			Fourth			December 31
		Quarter			Quarter			Quarter			Quarter
	2014:00:00
	Revenues	$	—		$	—		$	—		$	—		$	—
	Operating expenses		12,725			14,361			16,857			20,468			64,411
	Net loss		(11,842	)		(13,381	)		(15,875	)		(19,444	)		(60,542	)
	Net loss per share:
	Basic and Diluted	$	(0.17	)	$	(0.18	)	$	(0.21	)	$	(0.26	)	$	(0.81	)
	Shares used in the calculation of net loss per share:
	Basic and Diluted		70,260			75,879			75,948			76,139			74,577
	2013:00:00
	Revenues	$	730		$	730		$	729		$	730		$	2,919
	Operating expenses		13,705			13,897			12,735			12,260			52,597
	Net loss		(12,075	)		(12,242	)		(11,131	)		(10,642	)		(46,090	)
	Net loss per share:
	Basic and Diluted	$	(0.18	)	$	(0.18	)	$	(0.17	)	$	(0.16	)	$	(0.69	)
	Shares used in the calculation of net loss per share:
	Basic and Diluted		66,600			66,799			67,199			67,346			66,989

Recovered_Sheet1

Organization and Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Subsidiary
Organization And Summary Of Significant Accounting Policies [Line Items]
Number of subsidiary wholly-owned by company	2
Additional dilutive potential common shares			1,300,000
Diluted common shares outstanding	74,577,000	66,989,000	66,946,000
Anti-dilutive common stock share not included in computation of diluted earnings per share	1,000,000	300,000	2,200,000
Entity First Incorporation
Organization And Summary Of Significant Accounting Policies [Line Items]
Date of incorporation	1992
Place of incorporation	California
Entity Second Incorporation
Organization And Summary Of Significant Accounting Policies [Line Items]
Date of incorporation	1996
Place of incorporation	Delaware
Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Average estimated useful life of equipment	3 years
Requisite service period of award	3 years
Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Average estimated useful life of equipment	7 years
Requisite service period of award	4 years

Components_of_Investment_Incom

Components of Investment Income (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Interest income	$629	$400	$489
Realized gains, net	0	2	0
Total	$629	$402	$489

Recovered_Sheet2

Revenue Recognition and Significant Collaborative Research and Development Agreements - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2010	Oct. 31, 2007
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Sponsored research and development	$0	$0	$18,897,000
Dainippon Sumitomo Pharma Co Ltd
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative agreement maximum additional payment to receive					115,000,000
Up-front license fees					20,000,000
Recognized up-front license fees		2,900,000	2,900,000
AbbVie
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative agreement upfront payment received				75,000,000
Amount remains outstanding under collaboration agreement	500,000,000
Collaborative arrangement right description	The Company received funding for certain internal collaboration expenses which included reimbursement from AbbVie for internal and external expenses related to the GnRH Compounds through the end of 2012. The Company will be entitled to a percentage of worldwide sales of GnRH Compounds for the longer of ten years or the life of the related patent rights.
Patent rights period	Ten years or the life of the related patent rights
Collaboration termination notice period	180 days
Revenues recognized under the AbbVie collaboration agreement	0	0	46,900,000
Milestones and amortization of up-front license fees			29,100,000
Sponsored research and development			17,800,000
AbbVie | Collaboration
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Sponsored research and development			13,100,000
AbbVie | Development and regulatory event based payments
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative agreement maximum additional payment to receive				480,000,000
AbbVie | Commercial event based payments
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative agreement maximum additional payment to receive				$50,000,000

Investments_Detail

Investments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Investments [Line Items]
Investments	$200,287	$100,950
Certificates of deposit
Schedule of Investments [Line Items]
Investments	17,438	11,012
Commercial paper
Schedule of Investments [Line Items]
Investments	7,498	4,997
Corporate debt securities
Schedule of Investments [Line Items]
Investments	174,323	77,441
Securities of government-sponsored entities
Schedule of Investments [Line Items]
Investments	$1,028	$7,500

Summary_of_Investments_Classif

Summary of Investments Classified as Available-For-Sale Securities (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Aggregate Estimated Fair Value	$200,287		$100,950
Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Aggregate Estimated Fair Value	17,438		11,012
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Aggregate Estimated Fair Value	7,498		4,997
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Aggregate Estimated Fair Value	174,323		77,441
Securities of government-sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Aggregate Estimated Fair Value	1,028		7,500
Short-term investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	162,919		100,945
Gross Unrealized Gains	6	[1]	20	[1]
Gross Unrealized Losses	-130	[1]	-15	[1]
Aggregate Estimated Fair Value	162,795		100,950
Short-term investments | Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities contractual maturity	1 year		1 year
Amortized Cost	9,072		11,018
Gross Unrealized Gains	0	[1]	1	[1]
Gross Unrealized Losses	-6	[1]	-7	[1]
Aggregate Estimated Fair Value	9,066		11,012
Short-term investments | Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities contractual maturity	1 year		1 year
Amortized Cost	7,497		4,997
Gross Unrealized Gains	1	[1]	0	[1]
Gross Unrealized Losses	0	[1]	0	[1]
Aggregate Estimated Fair Value	7,498		4,997
Short-term investments | Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities contractual maturity	1 year		1 year
Amortized Cost	145,321		77,430
Gross Unrealized Gains	5	[1]	19	[1]
Gross Unrealized Losses	-123	[1]	-8	[1]
Aggregate Estimated Fair Value	145,203		77,441
Short-term investments | Securities of government-sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities contractual maturity	1 year		1 year
Amortized Cost	1,029		7,500
Gross Unrealized Gains	0	[1]	0	[1]
Gross Unrealized Losses	-1	[1]	0	[1]
Aggregate Estimated Fair Value	1,028		7,500
Long-term investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	37,645
Gross Unrealized Gains	0	[1]
Gross Unrealized Losses	-153	[1]
Aggregate Estimated Fair Value	37,492
Long-term investments | Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,400
Gross Unrealized Gains	0	[1]
Gross Unrealized Losses	-28	[1]
Aggregate Estimated Fair Value	8,372
Long-term investments | Certificates of deposit | Minimum
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities contractual maturity	1 year
Long-term investments | Certificates of deposit | Maximum
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities contractual maturity	2 years
Long-term investments | Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	29,245
Gross Unrealized Gains	0	[1]
Gross Unrealized Losses	-125	[1]
Aggregate Estimated Fair Value	$29,120
Long-term investments | Corporate debt securities | Minimum
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities contractual maturity	1 year
Long-term investments | Corporate debt securities | Maximum
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities contractual maturity	2 years
[1]	(1) Unrealized gains and losses are included in other comprehensive income.

Sales_and_Maturities_of_Availa

Sales and Maturities of Available-For-Sale Investments (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments Schedule [Abstract]
Proceeds from sales/maturities of available-for-sale securities	$154,133	$151,283	$132,520
Gross realized gains on sales of available-for-sale securities	0	2	0
Gross realized losses on sales of available-for-sale securities	0	0	0
Gains reclassified out of accumulated other comprehensive (loss) income into earnings	$0	$0	$0

AvailableForSale_Investments_i

Available-For-Sale Investments in Unrealized Loss Position (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value	$167,462	$39,721
Less Than 12 Months, Unrealized Losses	-283	-15
12 Months or Greater, Estimated Fair Value	0	0
12 Months or Greater, Unrealized Losses	0	0
Total Estimated Fair Value	167,462	39,721
Total Unrealized Losses	-283	-15
Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value	16,957	9,802
Less Than 12 Months, Unrealized Losses	-34	-7
12 Months or Greater, Estimated Fair Value	0	0
12 Months or Greater, Unrealized Losses	0	0
Total Estimated Fair Value	16,957	9,802
Total Unrealized Losses	-34	-7
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value	149,477	29,919
Less Than 12 Months, Unrealized Losses	-248	-8
12 Months or Greater, Estimated Fair Value	0	0
12 Months or Greater, Unrealized Losses	0	0
Total Estimated Fair Value	149,477	29,919
Total Unrealized Losses	-248	-8
Securities of government-sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Estimated Fair Value	1,028
Less Than 12 Months, Unrealized Losses	-1
12 Months or Greater, Estimated Fair Value	0
12 Months or Greater, Unrealized Losses	0
Total Estimated Fair Value	1,028
Total Unrealized Losses	($1)

Assets_Measured_at_Fair_Value_

Assets Measured at Fair Value on Recurring Basis (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	$200.30	$101
Investments Including Cash Equivalents And Restricted Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	236.1	150.2
Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	35.8	49.2
Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	193.8	145.8
Short-term investments | Cash and money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	28.7	34.9
Short-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	9.1	11
Short-term investments | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	7.5	5
Short-term investments | Securities of government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	1.5	7.5
Short-term investments | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	147	87.4
Long-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	13.2	4.4
Long-term investments | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	29.1
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	17.5	11
Quoted Prices in Active Markets for Identical Assets (Level 1) | Investments Including Cash Equivalents And Restricted Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	51	50.3
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	33.5	39.3
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	37.8	45.9
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | Cash and money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	28.7	34.9
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	9.1	11
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | Securities of government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	13.2	4.4
Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term investments | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	182.8	90
Significant Other Observable Inputs (Level 2) | Investments Including Cash Equivalents And Restricted Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	185.1	99.9
Significant Other Observable Inputs (Level 2) | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	2.3	9.9
Significant Other Observable Inputs (Level 2) | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	156	99.9
Significant Other Observable Inputs (Level 2) | Short-term investments | Cash and money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Other Observable Inputs (Level 2) | Short-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Other Observable Inputs (Level 2) | Short-term investments | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	7.5	5
Significant Other Observable Inputs (Level 2) | Short-term investments | Securities of government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	1.5	7.5
Significant Other Observable Inputs (Level 2) | Short-term investments | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	147	87.4
Significant Other Observable Inputs (Level 2) | Long-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Other Observable Inputs (Level 2) | Long-term investments | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	29.1
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Investments Including Cash Equivalents And Restricted Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Short-term investments | Cash and money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Short-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Short-term investments | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Short-term investments | Securities of government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Short-term investments | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Long-term investments | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Long-term investments | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	$0

Property_and_Equipment_Detail

Property and Equipment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property and equipment	$31,253	$30,103
Less accumulated depreciation	-28,746	-28,332
Property and equipment, net	2,507	1,771
Tenant improvements
Property, Plant and Equipment [Line Items]
Property and equipment	1,226	1,195
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment	819	819
Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$29,208	$28,089

Property_and_Equipment_Additio

Property and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Depreciation	$800,000	$700,000	$700,000
Gain (loss) on disposal of capital equipment	($4,000)	$37,000	$32,000

Accrued_Liabilities_Detail

Accrued Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Accrued employee related costs	$6,520	$3,403
Accrued development costs	1,706	1,387
Other accrued liabilities	3,282	3,165
Accrued Liabilities, Current	$11,508	$7,955

Recovered_Sheet3

Commitments and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended			1 Months Ended
	Dec. 31, 2007	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Aug. 31, 2012	Dec. 31, 2010	Sep. 30, 2011	Dec. 31, 2012	Nov. 30, 2012	Dec. 31, 2008
	Building	RenewalOptions				sqft	sqft	sqft		sqft
Commitment And Contingencies [Line Items]
Sale of facility and associated real property	$109,000,000
Mortgage debt retired	47,700,000
Cash received net of transaction costs and debt retirement	61,000,000
Leaseback transaction lease period	12 years
Number of building leased	2
Net deferred gain on real estate sale		17,600,000									39,100,000
Deferred gain recognized on real estate sale		3,200,000	3,100,000	3,000,000
Lease expiration year		2019
Percentage of management fee included in the base annual rent		3.50%
Letter of credit		4,600,000
Lease extension period		10 years
Number of times to renew the lease contract		2
Cease-use expense		0	0	1,092,000
Rent expense		5,900,000	5,900,000	5,900,000
Lease period		12 years
Lease expiration year		2019
Cash and investment required to be maintained		50,000,000
Security deposit to be increased		5,000,000
Milestone payables		17,000,000
Minimum
Commitment And Contingencies [Line Items]
Lease cancellation, notice period		0 days
Maximum
Commitment And Contingencies [Line Items]
Lease cancellation, notice period		180 days
Royalty, rate		5.00%
Sublease
Commitment And Contingencies [Line Items]
Subleased area						17,000	16,000
Rental income from sublease agreement							600,000
Sublease agreement period							3 years
Lease renewal additional periods							1 year
Cease-use expense						150,000	2,500,000
Deferred rent reversed					15,000		173,000
Second Sublease
Commitment And Contingencies [Line Items]
Subleased area								3,300
Rental income from sublease agreement								100,000
Sublease agreement period								3 years
Lease renewal additional periods								1 year
Cease-use expense								300,000
Deferred rent reversed								47,000
Third Sublease
Commitment And Contingencies [Line Items]
Subleased area										14,000
Rental income from sublease agreement										500,000
Sublease agreement period										3 years 6 months
Lease renewal additional periods										1 year
Cease-use expense										1,200,000
Deferred rent reversed									$250,000

Changes_to_Accrued_CeaseUse_Li

Changes to Accrued Cease-Use Liability (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Beginning balance	$3,096	$3,686
Payments	-418	-590
Ending balance	$2,678	$3,096

Estimated_Future_Annual_Minimu

Estimated Future Annual Minimum Lease Payments (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
2015	$7,385
2016	7,606
2017	7,834
2018	8,070
2019	8,311
Thereafter	0
Total future minimum lease payments	$39,206

ShareBased_Compensation_Additi

Share-Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	31-May-11
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock vesting period	4 years
Stock options outstanding	5,750,000	5,853,000	6,166,000	5,315,000
Number of common stock available for future grant	2,700,000
Share-based compensation, contractual term	10 years
Tax benefits recognized in the consolidated statements of cash flows	$0
Assumption estimated forfeiture rate	0.00%
Weighted-average fair values of options granted	$12.57	$6.55	$6.05
Weighted average remaining contractual term for options outstanding	6 years 4 months 24 days
Share-based compensation expense	10,382,000	6,819,000	5,479,000
Number of stock options exercisable	4,200,000
Stock options exercisable, weighted average exercise price	$7.55
Stock options exercisable, weighted-average remaining contractual term	5 years 7 months 6 days
Stock options exercised in period intrinsic value	14,300,000	6,000,000	943,000
Stock options intrinsic value of options outstanding	77,100,000
Stock options intrinsic value of options exercisable	64,300,000
Cash received from stock option exercises	5,600,000	5,300,000	700,000
Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation, term	3 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation, term	4 years
Share-based compensation, contractual term	10 years
Executive Level Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock options granted	160,000
Stock vesting period	4 years
Stock options outstanding	200,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	7,800,000
Unrecognized compensation cost	14,700,000
Stock vesting period	2 years 8 months 12 days
Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock vesting period	3 years
Share-based compensation, term	7 years
Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock vesting period	4 years
Share-based compensation, term	10 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Assumption estimated forfeiture rate	0.00%
Share-based compensation expense	2,600,000	800,000	0
Unrecognized compensation cost	7,500,000
Stock vesting period	2 years 10 months 24 days
Total intrinsic value vested in period	1,700,000	0	400,000
Intrinsic value outstanding	15,000,000
Restricted stock units granted	389,000	379,000	0
Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock vesting period	4 years
Performance-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock vesting period	5 years
Share-based compensation expense	0
Unrecognized compensation cost	9,300,000
Intrinsic value outstanding	$10,600,000
Restricted stock units granted	500,000
Performance-based RSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock vesting period	5 years
2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of common stock authorized for issuance					8,500,000
Share Based Compensation Arrangement Award
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of common stock authorized for issuance	9,500,000
Due to Changes in the Plan | Scenario, Previously Reported
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation, contractual term	7 years

Compensation_Expense_Related_t

Compensation Expense Related to Share-Based Compensation (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	$10,382,000	$6,819,000	$5,479,000
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	5,167,000	3,516,000	2,746,000
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	$5,215,000	$3,303,000	$2,733,000

WeightedAverage_Assumptions_fo

Weighted-Average Assumptions for Stock Option Grants using Black-Scholes Option-Pricing Model (Detail) (Stock Options)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	2.20%	1.40%	1.30%
Expected volatility of common stock	71.00%	76.00%	79.00%
Dividend yield	0.00%	0.00%	0.00%
Expected option term	7 years 2 months 12 days	7 years 3 months 18 days	6 years 9 months 18 days

Summary_and_Changes_in_Stock_O

Summary and Changes in Stock Options Outstanding (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Shares
Outstanding, Beginning Balance	5,853	6,166	5,315
Granted/amended	1,089	771	1,446
Exercised	-1,135	-904	-209
Canceled	-57	-180	-386
Outstanding, Ending Balance	5,750	5,853	6,166
Weighted average exercise price
Outstanding, Beginning Balance	$7.54	$7.62	$8.82
Granted/amended	$18.41	$9.24	$8.50
Exercised	$6.50	$5.96	$3.49
Canceled	$56.83	$25.68	$29.66
Outstanding, Ending Balance	$9.31	$7.54	$7.62

Summary_and_Changes_in_Restric

Summary and Changes in Restricted Stock Units Outstanding (Detail) (Restricted Stock Units (RSUs), USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock Units (RSUs)
Restricted stock units
Restricted stock units outstanding, Beginning Balance	373	0	50
Restricted stock units granted	389	379	0
Restricted stock units cancelled	0	-6	0
Restricted stock units converted into common shares	-93	0	-50
Restricted stock units outstanding Ending Balance	669	373	0
Weighted average grant date fair value
Restricted stock units outstanding Beginning Balance	$8.65	$0	$5.88
Restricted stock units granted	$19.59	$8.65	$0
Restricted stock units cancelled	$0	$8.65	$0
Restricted stock units converted into common shares	$8.65	$0	$5.88
Restricted stock units outstanding Ending Balance	$15.01	$8.65	$0

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	1 Months Ended		12 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Feb. 28, 2014	Jan. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Class of Stock [Line Items]
Common stock issued	8,000	10,900
Common stock, offering price	$17.75	$8.10
Proceeds from common stock issuance	$133,200,000	$83,000,000	$138,731,000	$5,302,000	$83,702,000
Shelf Registration
Class of Stock [Line Items]
Common stock issued			8,000
Shelf Registration | Maximum
Class of Stock [Line Items]
Aggregate initial offering price of common stock					$150,000,000

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Line Items]
Percentage of uncertain tax positions likelihood of being sustained	50.00%
Accrual interest or penalties	$0	$0
Deferred tax assets	367,100,000	341,700,000
Research and development tax credit carry forwards	29,000,000	27,700,000
Net operating loss carry forwards related to stock option exercises	26,500,000
Deferred tax assets, valuation allowance	367,100,000	341,700,000
Increases related to prior year tax positions	47,000	543,000	1,434,000
Increases related to current year tax positions	676,000	916,000	165,000
Unrecognized tax benefits that would affect effective tax rate	20,200,000
Federal
Income Taxes [Line Items]
Operating loss carry forward, net	668,300,000
Operating loss carry forward beginning expiration year	2021
Research and development tax credit carry forwards	33,900,000
Alternative Minimum Tax credit carry forwards	227,000
Federal | R&D
Income Taxes [Line Items]
Tax credit carry forwards beginning expiration year	2018
California
Income Taxes [Line Items]
Operating loss carry forward, net	652,800,000
Research and development tax credit carry forwards	$23,600,000

Expiration_of_Net_Operating_Lo

Expiration of Net Operating Loss Carry Forwards (Detail) (California, USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
California
Operating Loss Carryforwards [Line Items]
2015	$68,500
2016	113,400
2017	72,100
2018	140,600
2028 and beyond	$258,200

Components_of_Deferred_Tax_Ass

Components of Deferred Tax Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Net operating losses	$260,600	$246,500
Research and development credits	29,000	27,700
Capitalized research and development	45,700	34,500
Share-based compensation expense	6,900	5,200
Deferred revenue	800	800
Deferred gain on sales leaseback	7,200	8,500
Intangibles	10,600	13,200
Cease-use expense	1,100	1,300
Fixed assets	500	300
Other	4,700	3,700
Total deferred tax assets	367,100	341,700
Valuation allowance	-367,100	-341,700
Net deferred tax assets	$0	$0

Provision_for_Income_Taxes_on_

Provision for Income Taxes on Earnings Subject to Income Taxes Differs from Statutory Federal Rate (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal income taxes at 35%	($21,190)	($16,131)	$1,759
State income tax, net of Federal benefit	-3,410	-2,611	406
Tax effect on non-deductible expenses	10	7	9
Share-based compensation expense	91	215	1,154
Expired tax attributes	315	151	327
Research credits	-1,882	-3,458	-428
Change in valuation allowance	25,366	20,504	-4,061
Uncertain tax positions	621	1,283	876
Other	79	40	-42
Income Tax Expense (Benefit), Total	$0	$0	$0

Provision_for_Income_Taxes_on_1

Provision for Income Taxes on Earnings Subject to Income Taxes Differs from Statutory Federal Rate (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal income taxes, rate	35.00%	35.00%	35.00%

Activity_Related_to_Unrecogniz

Activity Related to Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Unrecognized tax benefit beginning Balance	$23,131	$21,672	$20,237
Increases related to prior year tax positions	47	543	1,434
Increases related to current year tax positions	676	916	165
Expiration of the statute of limitations for the assessment of taxes	0	0	-164
Unrecognized tax benefit ending Balance	$23,854	$23,131	$21,672

Retirement_Plan_Additional_Inf

Retirement Plan - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Defined contribution plan, maximum employee contribution percentage	60.00%
Defined contribution plan, employer contribution amount	$0.30	$0.30	$0.20

Summary_of_Quarterly_Results_o

Summary of Quarterly Results of Operations (Detail) (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 Information Disclosure [Abstract]
Revenues	$0	$0	$0	$0	$730	$729	$730	$730	$0	$2,919	$53,140
Operating expenses	20,468	16,857	14,361	12,725	12,260	12,735	13,897	13,705	64,411	52,597	51,692
Net loss	($19,444)	($15,875)	($13,381)	($11,842)	($10,642)	($11,131)	($12,242)	($12,075)	($60,542)	($46,090)	$5,025
Net loss per share:
Basic and Diluted	($0.26)	($0.21)	($0.18)	($0.17)	($0.16)	($0.17)	($0.18)	($0.18)	($0.81)	($0.69)
Shares used in the calculation of net loss per share:
Basic and Diluted	76,139	75,948	75,879	70,260	67,346	67,199	66,799	66,600	74,577	66,989