Segment Results - Schedule of Disaggregation of Revenues (Details) - USD ($)	3 Months Ended						6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 687,588,000				$ 699,727,000		$ 1,507,993,000	$ 1,420,138,000
Product line revenue reporting threshold	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	129,521,000				209,013,000		333,594,000	412,538,000
Branded Pharmaceuticals | Specialty Products
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	68,744,000				124,093,000		203,041,000	239,059,000
Branded Pharmaceuticals | XIAFLEX®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	33,783,000				74,855,000		122,855,000	143,362,000
Branded Pharmaceuticals | SUPPRELIN® LA
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	15,395,000				23,714,000		35,115,000	45,770,000
Branded Pharmaceuticals | Other Specialty
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	19,566,000				25,524,000		45,071,000	49,927,000
Branded Pharmaceuticals | Established Products
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	60,777,000				84,920,000		130,553,000	173,479,000
Branded Pharmaceuticals | PERCOCET®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	27,578,000				28,878,000		55,281,000	59,638,000
Branded Pharmaceuticals | LIDODERM®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	7,056,000				9,051,000		14,279,000	17,120,000
Branded Pharmaceuticals | EDEX®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	6,604,000				7,662,000		15,172,000	13,633,000
Branded Pharmaceuticals | Other Established
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	19,539,000				39,329,000		45,821,000	83,088,000
Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	319,214,000				244,280,000		655,604,000	514,328,000
Sterile Injectables | Vasostrict®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	214,214,000				116,026,000		417,118,000	255,163,000
Sterile Injectables | ADRENALIN®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	33,161,000				45,835,000		89,673,000	93,157,000
Sterile Injectables | Ertapenem for injection
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	11,990,000				25,547,000		29,864,000	57,766,000
Sterile Injectables | APLISOL®
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	6,511,000				15,530,000		16,378,000	27,911,000
Sterile Injectables | Other Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	53,338,000				41,342,000		102,571,000	80,331,000
Generic Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	215,879,000				$ 217,784,000		467,162,000	$ 436,310,000
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	$ 22,974,000				$ 28,650,000		$ 51,633,000	$ 56,962,000
International Pharmaceuticals | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	3.00%				4.00%			4.00%