Collaboration Agreements (Schedule Of Collaboration Revenue Attributable To Sales) (Detail) (United States XTANDI Sales [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Collaborative Arrangements [Line Items]
Shared U.S. development and commercialization costs	$ (88,908)
Pre-tax U.S. profit (loss)	(17,404)
Collaboration revenue attributable to U.S. XTANDI sales	35,752
Astellas [Member]
Collaborative Arrangements [Line Items]
Net U.S. sales (as reported by Astellas)	71,504
Medivation [Member]
Collaborative Arrangements [Line Items]
Medivation's share of pre-tax U.S. profit (loss)	(8,702)
Reimbursement of Medivation's share of shared U.S. costs	$ 44,454