LIABILITY RELATED TO SALE OF FUTURE ROYALTIES (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		12 Months Ended
	Oct. 18, 2013	Oct. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2014
Future royalties liability
Effective interest rate (as a percent)		10.00%
Non-cash PDL royalty revenue					$ 242,808
Non-cash interest expense on PDL liability					14,646
PDL BioPharma
Future royalties liability
Non-cash PDL royalty revenue					242,808
Liability related to sale of future royalties
Future royalties liability
Non-cash PDL royalty revenue			$ 147,000	$ 147,000	242,800
Non-cash interest expense on PDL liability					$ 14,600
Liability related to sale of future royalties | PDL BioPharma
Future royalties liability
Royalty and milestone payments received	$ 240,500	$ 240,500