Segment Results - Schedule of Disaggregation of Revenues (Details) - USD ($)	3 Months Ended							9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 634,860,000				$ 729,426,000			$ 2,142,853,000	$ 2,149,564,000
Product line revenue reporting threshold	25,000,000	$ 25,000,000	$ 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	223,682,000				217,313,000			557,276,000	629,851,000
Branded Pharmaceuticals | Specialty Products
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	140,120,000				131,998,000			343,161,000	371,057,000
Branded Pharmaceuticals | XIAFLEX®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	88,167,000				82,756,000			211,022,000	226,118,000
Branded Pharmaceuticals | SUPPRELIN® LA
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	28,229,000				20,772,000			63,344,000	66,542,000
Branded Pharmaceuticals | Other Specialty
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	23,724,000				28,470,000			68,795,000	78,397,000
Branded Pharmaceuticals | Established Products
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	83,562,000				85,315,000			214,115,000	258,794,000
Branded Pharmaceuticals | PERCOCET®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	27,508,000				28,561,000			82,789,000	88,199,000
Branded Pharmaceuticals | TESTOPEL®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	18,068,000				13,236,000			26,877,000	40,830,000
Branded Pharmaceuticals | Other Established
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	37,986,000				43,518,000			104,449,000	129,765,000
Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	251,393,000				263,635,000			906,997,000	777,963,000
Sterile Injectables | Vasostrict®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	155,412,000				129,691,000			572,530,000	384,854,000
Sterile Injectables | ADRENALIN®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	30,662,000				40,311,000			120,335,000	133,468,000
Sterile Injectables | Ertapenem for injection
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	16,784,000				21,853,000			46,648,000	79,619,000
Sterile Injectables | APLISOL®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	9,443,000				28,085,000			25,821,000	55,996,000
Sterile Injectables | Other Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	39,092,000				43,695,000			141,663,000	124,026,000
Generic Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	135,508,000				$ 218,012,000			602,670,000	$ 654,322,000
Generic Pharmaceuticals | Colchicine Tablets | Revenue Benchmark | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage					7.00%				6.00%
International Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 24,277,000				$ 30,466,000			$ 75,910,000	$ 87,428,000
International Pharmaceuticals | Revenue Benchmark | Product Concentration Risk | Maximum
Disaggregation of Revenue [Line Items]
Concentration risk, percentage								5.00%