Revenue Recognition - Schedule of Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Net revenue	$ 464,662	$ 404,642	$ 963,195	$ 850,762
Generics
Disaggregation of Revenue [Line Items]
Net revenue	306,559	335,064	659,145	717,541
Specialty
Disaggregation of Revenue [Line Items]
Net revenue	94,256	69,578	182,233	133,221
AvKARE
Disaggregation of Revenue [Line Items]
Net revenue	63,847		121,817
International and other | Generics
Disaggregation of Revenue [Line Items]
Net revenue	961	3,719	1,947	19,351
Anti-Infective | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	9,722	8,147	22,776	14,089
Hormonal/Allergy | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	89,277	92,293	177,919	195,018
Hormonal/Allergy | US | Specialty
Disaggregation of Revenue [Line Items]
Net revenue	13,669	9,888	27,623	20,787
Antiviral | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	955	1,346	16,779	15,802
Central Nervous System | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	96,228	117,398	195,810	242,173
Central Nervous System | US | Specialty
Disaggregation of Revenue [Line Items]
Net revenue	74,056	50,694	142,367	93,593
Cardiovascular System | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	25,105	31,138	54,359	67,355
Gastroenterology | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	16,625	9,938	37,878	19,494
Gastroenterology | US | Specialty
Disaggregation of Revenue [Line Items]
Net revenue	439	452	487	933
Oncology | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	16,567	21,746	31,422	36,705
Metabolic Disease/Endocrine | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	6,769	10,887	23,408	28,734
Metabolic Disease/Endocrine | US | Specialty
Disaggregation of Revenue [Line Items]
Net revenue	203	89	476	630
Respiratory | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	7,240	8,418	17,328	17,636
Dermatology | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	10,442	14,771	27,584	27,744
Other therapeutic classes | US | Generics
Disaggregation of Revenue [Line Items]
Net revenue	26,668	15,263	51,935	33,440
Other therapeutic classes | US | Specialty
Disaggregation of Revenue [Line Items]
Net revenue	5,889	$ 8,455	11,280	$ 17,278
Distribution | US | AvKARE
Disaggregation of Revenue [Line Items]
Net revenue	31,839		63,425
Government Label | US | AvKARE
Disaggregation of Revenue [Line Items]
Net revenue	25,073		46,451
Institutional | US | AvKARE
Disaggregation of Revenue [Line Items]
Net revenue	4,511		7,924
Other | US | AvKARE
Disaggregation of Revenue [Line Items]
Net revenue	$ 2,424		$ 4,017