Segment Results - Schedule of Disaggregation of Revenues (Details) - USD ($)	3 Months Ended							9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 729,426,000				$ 745,466,000			$ 2,149,564,000	$ 2,160,689,000
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	217,313,000				220,100,000			629,851,000	632,972,000
Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	263,635,000				237,150,000			777,963,000	670,847,000
Generic Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	218,012,000				257,969,000			654,322,000	748,445,000
International Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 30,466,000				$ 30,247,000			$ 87,428,000	$ 108,425,000
International Pharmaceuticals | Sales Revenue, Net | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	4.00%				4.00%			4.00%	5.00%
XIAFLEX® | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 82,756,000				$ 64,214,000			$ 226,118,000	$ 184,855,000
SUPPRELIN® LA | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	20,772,000				20,408,000			66,542,000	60,948,000
Other Specialty | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	28,470,000				27,614,000			78,397,000	69,226,000
Total Specialty Products | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	131,998,000				112,236,000			371,057,000	315,029,000
PERCOCET® | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	28,561,000				30,730,000			88,199,000	93,539,000
TESTOPEL® | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	13,236,000				15,962,000			40,830,000	44,976,000
Other Established | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	43,518,000				61,172,000			129,765,000	179,428,000
Total Established Products | Branded Pharmaceuticals
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	85,315,000				107,864,000			258,794,000	317,943,000
Vasostrict® | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	129,691,000				112,333,000			384,854,000	332,387,000
ADRENALIN® | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	40,311,000				35,460,000			133,468,000	101,858,000
APLISOL® | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	28,085,000				15,992,000			55,996,000	49,064,000
Ertapenem for injection | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	21,853,000				25,798,000			79,619,000	25,798,000
Other Sterile Injectables | Sterile Injectables
Disaggregation of Revenue [Line Items]
TOTAL REVENUES, NET	$ 43,695,000				$ 47,567,000			$ 124,026,000	$ 161,740,000
Colchicine Tablets | Generic Pharmaceuticals | Sales Revenue, Net | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	7.00%							6.00%