ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Government rebates payable	$ 5,614		$ 6,967
Compensation related costs	6,885		7,441
Accrued royalties and contingent consideration	6,144		5,766
Research and development	7,218		7,311
Selling, general and administrative	1,933		3,333
Restructuring expenses	2,551	$ 1,420	893
Miscellaneous accrued	1,908		1,597
Total accrued expenses	$ 32,253		$ 33,308