Collaboration Agreement - Collaboration Revenue and Collaboration Receivables - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue percentage of U.S. XTANDI net sales	50.00%	50.00%
Amortization of deferred upfront and development milestones		$ 1,411
Astellas Pharma Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development cost-sharing payments	$ 13,300	13,800
Commercialization cost-sharing payments	$ 18,700	20,100
Astellas Pharma Inc. [Member] \| Amortization of deferred upfront and development milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Amortization of deferred upfront and development milestones		$ 1,400
Development cost-sharing payments [Member] \| Collaborative agreement [Member] \| Medivation Inc [Member] \| U.S. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Share of XTANDI development and commercialization costs	50.00%
Development cost-sharing payments [Member] \| Collaborative agreement [Member] \| Medivation Inc [Member] \| ex-U.S. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Share of XTANDI development and commercialization costs	33.33%
Commercial cost sharing-payments [Member] \| Astellas Pharma Inc. [Member] \| Collaborative agreement [Member] \| U.S. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Share of XTANDI development and commercialization costs	50.00%
Commercial cost sharing-payments [Member] \| Astellas Pharma Inc. [Member] \| Collaborative agreement [Member] \| ex-U.S. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Share of XTANDI development and commercialization costs	66.67%

Commercialization cost sharing payments income (expense) under collaboration agreement.

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- Definition

Development cost sharing payments income (expense) under collaboration agreement.

+ References

No definition available.

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- Definition

Percentage of net sales of XTANDI in the United States, pursuant to collaboration agreement.

+ References

No definition available.

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- Definition

Share percentage of development and commercialization cost under collaboration arrangement.

+ References

No definition available.

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- Definition

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.

+ References

No definition available.

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 13.A.4(a).Q1)
-URI http://asc.fasb.org/extlink&oid=27012821&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 13
-Section A
-Subsection 1

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