INTANGIBLE ASSETS - Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Definite-Lived Intangible Assets:
Gross Carrying Amount	$ 500,489	$ 355,170
Accumulated Amortization	$ (206,367)	(166,659)
Weighted Average Amortization Period	9 years
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Amortization of intangible assets	$ 41,800	39,900	$ 40,200
Intangible asset impairment charge	2,374	446	$ 75
In process research and development
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Gross Carrying Amount	46,900
Acquired ANDA intangible assets
Definite-Lived Intangible Assets:
Gross Carrying Amount	168,536	106,415
Accumulated Amortization	$ (54,079)	(42,367)
Weighted Average Amortization Period	8 years 6 months
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Intangible asset impairment charge	$ 2,400
NDAs and product rights
Definite-Lived Intangible Assets:
Gross Carrying Amount	242,372	230,974
Accumulated Amortization	$ (138,835)	(112,483)
Weighted Average Amortization Period	9 years 10 months 24 days
Marketing and distribution rights
Definite-Lived Intangible Assets:
Gross Carrying Amount	$ 17,157	17,157
Accumulated Amortization	$ (12,347)	(11,386)
Weighted Average Amortization Period	5 years 6 months
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Intangible asset impairment charge		400
Non-compete agreement
Definite-Lived Intangible Assets:
Gross Carrying Amount	$ 624	624
Accumulated Amortization	$ (513)	$ (423)
Weighted Average Amortization Period	7 years
Customer Relationships
Definite-Lived Intangible Assets:
Gross Carrying Amount	$ 24,900
Accumulated Amortization	$ (593)
Weighted Average Amortization Period	7 years