Collaboration Agreement - Schedule of Collaboration Revenue (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Related to U.S. XTANDI sales	$ 71,866	$ 41,201	$ 134,091	$ 78,890
Related to ex-U.S. XTANDI sales	9,992	482	15,723	482
Related to upfront and milestone payments	66,232	28,466	85,465	36,931
Collaboration revenue	$ 148,090	$ 70,149	$ 235,279	$ 116,303

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