Collaboration Agreements - Schedule of Collaboration Revenue (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	$ 96,612	$ 60,027	$ 70,149	$ 46,154	$ 37,161	$ 64,798	$ 42,912	$ 36,825	$ 272,942	$ 181,696	$ 60,389
U.S. XTANDI sales [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue									196,208	35,752
Ex-U.S Xtandi sales [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue									6,338
Up-front cash payment arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue									$ 70,396	$ 145,944	$ 60,389