INTANGIBLE ASSETS - Definite-lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
INTANGIBLE ASSETS
Gross Carrying Amount	$ 307,225	$ 288,215
Accumulated Amortization	$ (126,837)	(86,611)
Weighted Average Amortization Period	10 years
Acquired ANDA intangible assets [Member]
INTANGIBLE ASSETS
Gross Carrying Amount	$ 64,704	46,194
Accumulated Amortization	$ (30,169)	(17,093)
Weighted Average Amortization Period	10 years
NDAs and product rights
INTANGIBLE ASSETS
Gross Carrying Amount	$ 230,974	230,974
Accumulated Amortization	$ (87,352)	(62,222)
Weighted Average Amortization Period	10 years
Marketing and distribution rights
INTANGIBLE ASSETS
Gross Carrying Amount	$ 10,923	10,423
Accumulated Amortization	$ (8,982)	(7,051)
Weighted Average Amortization Period	4 years 8 months 12 days
Non-compete agreement
INTANGIBLE ASSETS
Gross Carrying Amount	$ 624	624
Accumulated Amortization	$ (334)	$ (245)
Weighted Average Amortization Period	7 years