COLLABORATION AGREEMENT (Details) (Collaborations, USD $) In Millions, unless otherwise specified		9 Months Ended	1 Months Ended
	Sep. 30, 2011 GlaxoSmithKline TrobaltTM Year	Sep. 30, 2011 GlaxoSmithKline PotigaTM Year	Jun. 30, 2011 Meda Pharma GmbH & Co. KG (Meda Pharma) PotigaTM
Collaboration Agreement
Minimum age limit for adjunctive treatment with epilepsy (in years)	18	18
GSK milestone payment, maximum percentage of royalty on net sales of product (as a percent)	20.00%
GSK milestone payment, maximum percentage of net profits shared on sales of product (as a percent)		50.00%
Milestone payment made		$ 45.0	$ 6.0