Collaboration Agreements - Schedule of Collaboration Revenue Related to U.S. XTANDI Sales (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue related to U.S. XTANDI sales	$ 339,902	$ 196,208	$ 35,752
U.S. XTANDI sales [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue related to U.S. XTANDI sales	339,902	196,208	35,752
U.S. XTANDI sales [Member] \| Astellas Pharma Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
U.S. XTANDI sales (as reported by Astellas)	679,805	392,415	71,504
Shared U.S. development and commercialization costs	(323,730)	(241,106)	(88,908)
Pre-tax U.S. profit (loss)	356,075	151,309	(17,404)
U.S. XTANDI sales [Member] \| Medivation [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Medivation's share of pre-tax U.S. profit (loss)	178,037	75,655	(8,702)
Reimbursement of Medivation's share of shared U.S. costs	$ 161,865	$ 120,553	$ 44,454

Collaboration revenue related to net XTANDI sales in the United States.

No definition available.

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- Definition

pre-tax U.S. profit or loss under collaboration agreement with Astellas

+ References

No definition available.

+ Details

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- Definition

U.S. Net sales of XTANDI as reported by collaboration partner, Astellas

+ References

No definition available.

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- Definition

shared U.S. commercialization costs for XTANDI and development costs for XTANDI and enzalutamide

+ References

No definition available.

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- Definition

Medivation's share of pre-tax U.S. profit or loss under collaboration agreement with Astellas

+ References

No definition available.

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- Definition

Repayment received or receivable for expenses incurred on behalf of a client or customer, other than those reimbursements received by landlords from tenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 45

-Section 45

-Paragraph 23

-URI http://asc.fasb.org/extlink&oid=21915142&loc=d3e60722-111653

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