Collaboration Agreement - Schedule of Collaboration Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Related to U.S. XTANDI net sales	$ 149,220	$ 71,866	$ 261,230	$ 134,091
Related to ex-U.S. XTANDI net sales	25,591	9,992	41,358	15,723
Related to upfront and milestone payments	846	66,232	2,257	85,465
Collaboration revenue	$ 175,657	$ 148,090	$ 304,845	$ 235,279

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