QUARTERLY FINANCIAL DATA (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
QUARTERLY FINANCIAL DATA
Net Revenues	$ 57,252	$ 52,979	$ 48,470	$ 49,774	$ 47,966	$ 51,337	$ 54,357	$ 52,887	$ 208,475	$ 206,547	$ 201,576
Total operating expenses	56,921	50,177	59,777	57,616	52,637	44,009	45,065	48,485	224,491	190,196	166,217
Operating (loss)/ income	331	2,802	(11,307)	(7,842)	(4,671)	7,328	9,292	4,402	(16,016)	16,351	35,359
Benefit/(provision) for income taxes	(1,253)	371	1,443	2,853	2,817	(64)	653	(469)	3,414	2,937	(4,557)
Net (loss)/income	$ (3,635)	$ 434	$ (12,336)	$ (7,011)	$ (4,835)	$ 3,895	$ 6,585	$ 449	$ (22,548)	$ 6,094	$ 15,494
Basic and diluted (loss)/earnings per share:
Basic earnings/(loss) per share	$ (0.30)	$ 0.04	$ (1.03)	$ (0.59)	$ (0.41)	$ 0.32	$ 0.55	$ 0.04	$ (1.88)	$ 0.51	$ 1.31
Diluted (Loss)/Earnings Per Share	$ (0.30)	$ 0.04	$ (1.03)	$ (0.59)	$ (0.41)	$ 0.32	$ 0.53	$ 0.04	$ (1.88)	$ 0.50	$ 1.30
Inventory reserve charges					$ 4,600
Cortrophin pre-launch charges					$ 6,500				$ 11,263	$ 6,706