RESTRUCTURING - 2020 Restructuring Initiative (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended		21 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) position	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation	$ 6,400	$ 6,300	$ 22,300	$ 14,700
Asset impairments	42,155	8,412	50,393	106,197
Assets held for sale	39,952		$ 39,952		$ 39,952	$ 0
2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected number of positions eliminated | position			500
Restructuring charges	35,952	67,329	$ 67,850	75,714
Accelerated depreciation	6,350	6,291	22,329	14,676
Asset impairments	42,155	7,391	42,155	7,391	50,000
Restructuring reserve, current	23,100		23,100		23,100
2020 Restructuring Initiative | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(11,050)	36,172	9,294	42,198
2020 Restructuring Initiative | Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4,946	20,185	15,174	22,130
Minimum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	85,000		85,000		85,000
Restructuring charges			170,000
Accelerated depreciation			45,000
Payments for restructuring			80,000
Employee separation, continuity and other benefit-related costs			60,000
Minimum | 2020 Restructuring Initiative | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	65,000		65,000		65,000
Minimum | 2020 Restructuring Initiative | Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	20,000		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		95,000
Restructuring charges			190,000
Accelerated depreciation			55,000
Employee separation, continuity and other benefit-related costs			65,000
Maximum | 2020 Restructuring Initiative | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	70,000		70,000		70,000
Maximum | 2020 Restructuring Initiative | Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost savings	25,000		25,000		25,000
Certain Other Restructuring Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	24,800	3,400	37,500	9,800
Certain Other Restructuring Costs | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			2,731
Payments for restructuring			3,168
Restructuring and related cost, cost incurred to date	3,700		3,700		3,700
Certain Other Restructuring Costs | Minimum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			15,000
Certain Other Restructuring Costs | Maximum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			20,000
Accelerated depreciation | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cost incurred to date	44,800		44,800		44,800
Asset impairments | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cost incurred to date	49,500		49,500		49,500
Increase in excess inventory reserves | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cost incurred to date	9,600		9,600		9,600
Employee Separation, Continuity and Other Benefit-Related Costs | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			(6,150)
Payments for restructuring			28,957
Restructuring and related cost, cost incurred to date	53,900		53,900		53,900
Operating segments | Generic Pharmaceuticals | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges	31,000	$ 57,800	53,500	$ 66,200
Restructuring and related cost, cost incurred to date	$ 132,400		132,400		$ 132,400
Operating segments | Generic Pharmaceuticals | Minimum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			145,000
Operating segments | Generic Pharmaceuticals | Maximum | 2020 Restructuring Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 160,000