Collaboration Agreements - Schedule of Collaboration Revenue (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Collaborative Arrangements [Line Items]
Total	$ 46,154	$ 36,825
U.S. XTANDI sales [Member]
Collaborative Arrangements [Line Items]
Attributable to U.S. XTANDI sales	37,689
Attributable to ex-U.S. XTANDI sales
Up-front cash payment arrangement [Member]
Collaborative Arrangements [Line Items]
Attributable to up-front and milestone payments	$ 8,465	$ 36,825