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Deferred Revenue Creditable Against Future Milestones

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Deferred Revenue, Remaining Recognition Period

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Fair Value Inputs Period

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Issuance of common stock price per share.

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Percentage Of Costs Funded In License Agreement

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Research and Development Plan, Expected Term

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Revenue Recognition, Milestone Method, Expected Milestone Receivable

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Royalty Percentage Based On Net Sales

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.

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Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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Amount of previously reported deferred or unearned revenue that was recognized as revenue during the period. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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Cash received from collaborators during the current period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The amount of previously reported deferred or unearned revenue that was recognized as revenue during the period. For cash flows, this element primarily pertains to amortization of deferred credits on long-term arrangements. As a noncash item, it is deducted from net income when calculating cash provided by or used in operations using the indirect method.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The amount of consideration recognized during the period for the milestone or milestones.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Strategic Alliances and Collaborations (Detail)	1 Months Ended											3 Months Ended		8 Months Ended
Strategic Alliances and Collaborations (Detail)	Dec. 31, 2015 USD ($) shares	Sep. 30, 2015 USD ($)	Jul. 31, 2015	May. 31, 2015 USD ($)	Mar. 31, 2015 USD ($)	Jan. 31, 2015 USD ($)	Aug. 31, 2014 USD ($)	Feb. 28, 2014 USD ($) $ / shares shares	Jul. 31, 2013 USD ($)	Oct. 31, 2012 USD ($) $ / shares shares	Aug. 31, 2012 USD ($) agreement	Mar. 31, 2016 USD ($) shares	Mar. 31, 2015 USD ($)	Jan. 31, 2014 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Common stock value	$ 53,000											$ 53,000
Common stock, shares issued \| shares	52,669,266											52,774,550
AstraZeneca
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of collaborative areas granted \| agreement											3
Initial upfront option payment										$ 3,000,000
Expected term of research and development plan (years)										4 years
Common stock value											$ 25,000,000
Common stock, shares issued \| shares										6,250,000
Price per share (in dollars per share) \| $ / shares										$ 4.00
Restriction period in which Alliances could not sell, transfer, make any short sale of, or grant any option for the sale of any common stock										365 days
Restricting common stock valuation measurement period										1 year
Deferred revenue										$ 4,300,000
Deferred revenue remaining recognition period												5 months
Expected revenue through milestone payments												$ 485,500,000
AstraZeneca \| Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalties based on percentage of net sales												10.00%
AstraZeneca \| Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalties based on percentage of net sales												20.00%
AstraZeneca \| Common Stock Purchase Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue												$ 700,000
AstraZeneca \| Preclinical
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments, earned					$ 2,500,000
Expected revenue through milestone payments												2,500,000
AstraZeneca \| Clinical
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments, earned	$ 10,000,000
Expected revenue through milestone payments												113,000,000
AstraZeneca \| Commercialization
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Expected revenue through milestone payments												$ 370,000,000
AstraZeneca \| Side Letter
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognized													$ 600,000
AstraZeneca \| Side Letter \| Pre-IND and API manufacturing activities
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of cost funded						50.00%
AstraZeneca \| Side Letter \| Phase I clinical study product manufacturing activities
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of cost funded						100.00%
Sanofi
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue								$ 400,000
Sanofi \| Private Placement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Common stock value								$ 10,000,000
Common stock, shares issued \| shares								1,303,780
Price per share (in dollars per share) \| $ / shares								$ 7.67
Restriction period in which Alliances could not sell, transfer, make any short sale of, or grant any option for the sale of any common stock								12 months
Sanofi \| Minimum \| United States
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalties based on percentage of net sales												10.00%
Sanofi \| Minimum \| Outside of the United States
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalties based on percentage of net sales												10.00%
Sanofi \| Maximum \| United States
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalties based on percentage of net sales												20.00%
Sanofi \| Maximum \| Outside of the United States
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalties based on percentage of net sales												20.00%
Sanofi \| Development Commercialization And License Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Initial upfront option payment									$ 2,500,000
Milestone payments, earned								$ 2,500,000
Deferred Revenue Creditable Against Future Milestones								$ 1,250,000	$ 1,250,000			$ 1,250,000
Upfront payment non-creditable portion recognized														$ 1,250,000
Sanofi \| Common Stock Purchase Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue												$ 300,000
Deferred revenue remaining recognition period												4 years
Sanofi \| Clinical
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Expected revenue through milestone payments												$ 15,000,000
Sanofi \| Proof-of-Concept Trial
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Expected revenue through milestone payments												101,800,000
Sanofi \| Regulatory and Commercialization Milestones
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Expected revenue through milestone payments												$ 300,000,000
Biogen
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Initial upfront option payment							$ 2,000,000
Deferred revenue	$ 0
Deferred revenue remaining recognition period			14 months				1 year				12 months
Biogen \| Research and development
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments, earned		$ 300,000		$ 300,000		$ 100,000
Revenue recognized							$ 2,000,000