RESTRUCTURING AND INTEGRATION (Details 2) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010
Cost-rationalization and integration initiatives
Amount of negotiated settlement on termination of contract		$ 55,582,000	$ 56,443,000
Internal and external costs incurred	5,300,000
Charge for remaining operating lease obligation, net of sublease income		46,941,000	134,821,000
Restructuring Reserve, Settled without Cash		4,665,000	51,919,000
Staccato Loxapine
Cost-rationalization and integration initiatives
Contingent Milestone Obligations Terminated		90,000,000
AMPAKINE
Cost-rationalization and integration initiatives
Contingent Milestone Obligations Terminated		15,000,000
GDNF
Cost-rationalization and integration initiatives
Contingent Milestone Obligations Terminated		20,000,000
Fipamezole
Cost-rationalization and integration initiatives
Contingent Milestone Obligations Terminated		200,000,000
Pimavanserin
Cost-rationalization and integration initiatives
Contingent Milestone Obligations Terminated		365,000,000
IPR&D Termination Costs
Cost-rationalization and integration initiatives
Amount of negotiated settlement on termination of contract			13,750,000
Charge for remaining operating lease obligation, net of sublease income			13,750,000
IPR&D Termination Costs | GDNF
Cost-rationalization and integration initiatives
Amount of negotiated settlement on termination of contract	5,000,000
Carrying amount		5,000,000
IPR&D Termination Costs | Tetrabenazine
Cost-rationalization and integration initiatives
Carrying amount		28,000,000
IPR&D Termination Costs | Pimavanserin
Cost-rationalization and integration initiatives
Amount of negotiated settlement on termination of contract	8,750,000
Carrying amount		8,750,000
Contract Termination, Facility Closure and Other Costs
Cost-rationalization and integration initiatives
Amount of negotiated settlement on termination of contract		15,381,000	8,755,000
Charge for remaining operating lease obligation, net of sublease income		28,938,000	12,862,000
Reversal of previously recognized restructuring accrual		2,000,000
Integration-related costs incurred		50,900,000
Integration-related costs paid		37,500,000
Restructuring Reserve, Settled without Cash		4,913,000	2,437,000
Operating lease obligation
Cost-rationalization and integration initiatives
Charge for remaining operating lease obligation, net of sublease income		9,800,000
Lease termination
Cost-rationalization and integration initiatives
Charge for remaining operating lease obligation, net of sublease income		$ 1,400,000