ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Compensation related costs	$ 7,749	$ 7,441
Research and development	6,989	7,311
Government rebate reserves	5,883	6,967
Selling, general and administrative	3,896	3,333
Royalty/contingent consideration	6,429	5,766
Restructuring reserve	3,549	893
Miscellaneous accrued expenses	1,523	1,597
Total accrued expenses	$ 36,018	$ 33,308