GOODWILL AND OTHER INTANGIBLE ASSETS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Goodwill [Line Items]
Expected annual amortization expense, 2019	$ 49,500
Expected annual amortization expense, 2020	65,800
Expected annual amortization expense, 2021	64,700
Expected annual amortization expense, 2022	61,200
Expected annual amortization expense, 2023	60,300
Expected annual amortization expense, 2024	59,500
Expected annual amortization expense, thereafter	535,900
Total revenue, net	359,690	$ 357,082
Acquired intangible asset associated with customer received notification from the FDA	1,058,630		$ 1,079,496
Customer Relationships
Goodwill [Line Items]
Acquired intangible asset associated with customer received notification from the FDA	120,592		124,589
Contract Manufacturing Customer, Notified By FDA To Remove Product From Market | Private Label
Goodwill [Line Items]
Total revenue, net	600		$ 1,700
Contract Manufacturing Customer, Notified By FDA To Remove Product From Market | Customer Relationships | Private Label
Goodwill [Line Items]
Acquired intangible asset associated with customer received notification from the FDA	$ 5,900