Collaboration Agreement - Schedule of Collaboration Revenue (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Related to U.S. XTANDI net sales	$ 112,010	$ 62,225
Related to ex-U.S. XTANDI net sales	15,767	5,731
Related to upfront and milestone payments	1,411	19,233
Collaboration revenue	$ 129,188mdvn_CollaborationRevenue	$ 87,189mdvn_CollaborationRevenue

Revenue earned from the amortization of non refundable upfront cash payment received under collaboration agreements over the expected performance period and milestone payments earned.

No definition available.

Name:	mdvn_CollaborationRevenueRelatedToUpFrontAndMilestonePayments
Namespace Prefix:	mdvn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration