DISPOSITIONS - Sale of Gralise (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 10, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Co-promotion service income	$ 253			$ (764)	$ (3,571)	$ (2,613)
Gralise | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration received, including base purchase price and inventory adjustment							$ 78,600
Consideration received, base purchase price							75,000
Consideration received, inventory adjustment upon disposal							$ 3,600
Consideration receivable as percentage of net sales after closing							75.00%
Threshold for consideration receivable on net sales after closing							$ 70,000
Net sale after closing, contingent consideration							$ 52,500
Adjustment to gain on sale		$ 900
Contingent consideration, payments received					$ 51,600
Gain (loss) on disposal			$ 127,500
Co-promotion service income			$ 1,300