Segment Results - Schedule of Disaggregation of Revenues (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 820,405,000				$ 720,411,000
Product line revenue reporting threshold	25,000,000	$ 25,000,000	$ 25,000,000	$ 25,000,000	25,000,000
Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	204,073,000				203,525,000
Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	336,390,000				270,048,000
Generic Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	251,283,000				218,526,000
International Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 28,659,000				$ 28,312,000
International Pharmaceuticals | Revenue Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	3.00%				4.00%
Specialty Products | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 134,297,000				$ 114,966,000
XIAFLEX® | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	89,072,000				68,507,000
SUPPRELIN® LA | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	19,720,000				22,056,000
Other Specialty | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	25,505,000				24,403,000
Established Products | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	69,776,000				88,559,000
PERCOCET® | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	27,703,000				30,760,000
EDEX® | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	8,568,000				5,971,000
Other Established | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	33,505,000				51,828,000
Vasostrict® | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	202,904,000				139,137,000
ADRENALIN® | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	56,512,000				47,322,000
Ertapenem for injection | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	17,874,000				32,219,000
APLISOL® | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	9,867,000				12,381,000
Other Sterile Injectables | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 49,233,000				$ 38,989,000
Colchicine Tablets | Generic Pharmaceuticals | Revenue Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	6.00%