Segment Information - Schedules of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Net revenue	$ 464,662	$ 404,642	$ 963,195	$ 850,762
Cost of goods sold	319,666	296,381	633,244	606,124
Cost of goods sold impairment charges	759	3,012	2,215	56,309
Gross profit	144,237	105,249	327,736	188,329
Selling, general and administrative	80,944	67,281	158,920	151,717
Research and development	45,572	48,016	81,951	101,874
In-process research and development impairment charges	0	0	960	22,787
Intellectual property legal development expenses	3,550	2,511	4,820	6,677
Acquisition, transaction-related and integration expenses	1,787	3,519	4,362	9,551
Charges (gains) related to legal matters, net	1,300	0	5,800	0
Other operating expenses	2,120		6,743
Restructuring and other charges	333	2,835	2,381	8,996
Operating income (loss)	10,751	(18,913)	68,542	(113,273)
Generics
Segment Reporting Information [Line Items]
Net revenue	306,559	335,064	659,145	717,541
AvKARE
Segment Reporting Information [Line Items]
Net revenue	63,847		121,817
Operating Segments | Generics
Segment Reporting Information [Line Items]
Net revenue	306,559	335,064	659,145	717,541
Cost of goods sold	218,909	263,423	437,774	542,301
Cost of goods sold impairment charges	759	3,012	2,215	56,309
Gross profit	86,891	68,629	219,156	118,931
Selling, general and administrative	12,802	14,379	29,425	38,527
Research and development	40,316	45,448	69,350	95,599
In-process research and development impairment charges			960	22,787
Intellectual property legal development expenses	3,550	2,511	4,815	5,632
Acquisition, transaction-related and integration expenses		987		3,584
Charges (gains) related to legal matters, net	3,050		5,550
Other operating expenses	657		703
Restructuring and other charges		418		2,499
Operating income (loss)	26,516	4,886	108,353	(49,697)
Operating Segments | Specialty
Segment Reporting Information [Line Items]
Net revenue	94,256	69,578	182,233	133,221
Cost of goods sold	50,229	32,958	98,047	63,823
Cost of goods sold impairment charges	0	0	0	0
Gross profit	44,027	36,620	84,186	69,398
Selling, general and administrative	16,870	16,150	37,812	37,477
Research and development	5,256	2,568	12,601	6,275
In-process research and development impairment charges			0	0
Intellectual property legal development expenses	0	0	5	1,045
Acquisition, transaction-related and integration expenses		1,366		3,250
Charges (gains) related to legal matters, net	(1,750)		250
Other operating expenses	82		82
Restructuring and other charges		0		178
Operating income (loss)	23,569	16,536	33,436	21,173
Operating Segments | AvKARE
Segment Reporting Information [Line Items]
Net revenue	63,847		121,817
Cost of goods sold	50,528		97,423
Cost of goods sold impairment charges	0		0
Gross profit	13,319		24,394
Selling, general and administrative	15,647		26,435
Research and development	0		0
In-process research and development impairment charges			0
Intellectual property legal development expenses	0		0
Charges (gains) related to legal matters, net	0		0
Other operating expenses	0		0
Operating income (loss)	(2,328)		(2,041)
Corporate and Other
Segment Reporting Information [Line Items]
Net revenue	0	0	0	0
Cost of goods sold	0	0	0	0
Cost of goods sold impairment charges	0	0	0	0
Gross profit	0	0	0	0
Selling, general and administrative	35,625	36,752	65,248	75,713
Research and development	0	0	0	0
In-process research and development impairment charges			0	0
Intellectual property legal development expenses	0	0	0	0
Acquisition, transaction-related and integration expenses		1,166		2,717
Charges (gains) related to legal matters, net	0		0
Other operating expenses	1,381		5,958
Restructuring and other charges		2,417		6,319
Operating income (loss)	$ (37,006)	$ (40,335)	$ (71,206)	$ (84,749)