INTANGIBLE ASSETS - Summary of Gross Carrying Amounts and net Book Values of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Intangible assets
Gross Carrying Amount	$ 908,798	$ 1,098,588
Accumulated Amortization	(516,058)	(508,263)
Disposition	(369,069)
Impairment		(189,790)
Total	23,671	400,535
NUCYNTA \| Product rights
Intangible assets
Gross Carrying Amount	830,188	1,019,978
Accumulated Amortization	(461,119)	(455,192)
Disposition	(369,069)
Impairment		(189,790)
Total	$ 0	374,996
CAMBIA \| Product rights
Intangible assets
Remaining Useful Life (In years)	3 years 8 months 12 days
Gross Carrying Amount	$ 51,360	51,360
Accumulated Amortization	(32,311)	(31,027)
Total	$ 19,049	20,333
Zipsor \| Product rights
Intangible assets
Remaining Useful Life (In years)	2 years
Gross Carrying Amount	$ 27,250	27,250
Accumulated Amortization	(22,628)	(22,044)
Total	$ 4,622	$ 5,206

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

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-Publisher FASB
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