Sale of HIV Protease Inhibitor Royalty Stream (Details) (USD $) In Millions	12 Months Ended
	Dec. 31, 2008	Sep. 30, 2011
Sale of HIV Protease Inhibitor Royalty Stream
Gross proceeds from sale of royalty rights receivable from GlaxoSmithKline	$ 160.0
Deferred revenues related to the one-time cash payment agreement with GlaxoSmithKline		$ 99.7