CAPITALIZED FEES PAID TO A RELATED PARTY (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Capitalized Fees paid to a Related Party
Capitalized fees paid to a related party, useful life	15 years
Net carrying value	$ 180,545	$ 194,368
Weighted average remaining amortization period	13 years 1 month 6 days
Amortization expense	$ 13,823	13,823	$ 11,066
Capitalized Fees paid to a Related Party, Future amortization
Estimated amortization expense for the year 2017	13,800
Estimated amortization expense for the year 2018	13,800
Estimated amortization expense for the year 2019	13,800
Estimated amortization expense for the year 2020	13,800
Estimated amortization expense for the year 2021	13,800
Estimated amortization expense thereafter	111,400
GSK
Capitalized Fees paid to a Related Party
Gross carrying value	220,000	220,000
Accumulated amortization	(39,455)	(25,632)
Net carrying value	180,545	194,368
GSK | United States
Capitalized Fees paid to a Related Party
Gross carrying value	120,000	120,000
GSK | Europe
Capitalized Fees paid to a Related Party
Gross carrying value	60,000	60,000
GSK | Japan
Capitalized Fees paid to a Related Party
Gross carrying value	$ 40,000	$ 40,000