Segment Results - Schedule of Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 720,411		$ 700,527
Product line revenue reporting threshold	25,000	$ 25,000
Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	203,525		200,235
Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	270,048		215,854
Generic Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	218,526		249,240
International Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	28,312		35,198
XIAFLEX® | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	68,507		57,141
SUPPRELIN® LA | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	22,056		20,577
Other Specialty | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	24,403		19,027
Total Specialty Products | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	114,966		96,745
PERCOCET® | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	30,760		31,976
TESTOPEL® | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	15,814		15,170
Other Established | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	41,985		56,344
Total Established Products | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	88,559		103,490
Vasostrict® | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	139,137		113,725
ADRENALIN® | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	47,322		29,740
Ertapenem for injection | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	32,219		0
Other Sterile Injectables | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 51,370		$ 72,389
Sales Revenue, Net | Product Concentration Risk | International Pharmaceuticals
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	4.00%		5.00%
Sales Revenue, Net | Product Concentration Risk | Colchicine Tablets | Generic Pharmaceuticals
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	6.00%