BUSINESS COMBINATIONS (Details 11) (USD $)	12 Months Ended			3 Months Ended		12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Jun. 30, 2009 Tetrabenazine	Dec. 31, 2011 Tetrabenazine	Dec. 31, 2011 Tetrabenazine BVF-018	Dec. 31, 2011 Tetrabenazine RUS-350	Dec. 31, 2011 Tetrabenazine Product rights Y
Business Combinations
Cash consideration					$ 200,000,000
Additional cash payments on first anniversary					12,500,000
Additional cash payments on first anniversary					17,500,000
Fair value of contingent payments					26,800,000
Acquisition-related costs	32,964,000	38,262,000	5,596,000	5,600,000
Assets acquired
Inventories					1,100,000
Intangible assets:
Identifiable intangible assets								189,700,000
Acquired IPR&D					36,000,000	28,000,000	8,000,000
Estimated weighted-average useful life (in years)								9
Risk-adjusted discount rate					20.00%
Acquired in-process research and development	$ 109,200,000	$ 89,245,000	$ 59,354,000			$ 28,000,000	$ 8,000,000