Restructuring - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) position	Sep. 30, 2019 USD ($)
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation charges	$ 6,300		$ 14,700
Asset impairment charges	8,412	$ 4,766	$ 106,197	$ 258,652
2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected number of positions eliminated | position			560
Restructuring charges	67,329		$ 75,714
Accelerated depreciation charges	6,291		14,676
Asset impairment charges	7,391		7,391
Employee separation, continuity and other benefit-related costs	53,647		53,647
Restructuring reserve, current	29,500		29,500
Cost of revenues | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges	36,172		42,198
Selling, general and administrative | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges	20,185		22,130
Minimum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	85,000		85,000
Restructuring charges			163,000
Accelerated depreciation charges			56,000
Employee separation, continuity and other benefit-related costs			85,000
Payments for restructuring			100,000
Minimum | Cost of revenues | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	65,000		65,000
Minimum | Selling, general and administrative | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	20,000		20,000
Maximum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	95,000		95,000
Restructuring charges			183,000
Accelerated depreciation charges			66,000
Employee separation, continuity and other benefit-related costs			90,000
Payments for restructuring			110,000
Maximum | Cost of revenues | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	70,000		70,000
Maximum | Selling, general and administrative | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	25,000		25,000
Employee separation, continuity and other benefit-related costs | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			53,647
Restructuring and related cost, cost incurred to date	53,600		53,600
Other restructuring charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3,400	$ 4,300	9,800	$ 6,300
Other restructuring charges | Minimum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			15,000
Other restructuring charges | Maximum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			20,000
Accelerated depreciation charges | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cost incurred to date	14,700		14,700
Asset impairment charges | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cost incurred to date	7,400		7,400
Generic Pharmaceuticals | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges	57,800		66,200
Restructuring and related cost, cost incurred to date	$ 66,200		66,200
Operating segments | Generic Pharmaceuticals | Minimum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			125,000
Operating segments | Generic Pharmaceuticals | Maximum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 140,000