ACQUISITIONS AND DISPOSITIONS - Acquisition of Liquid Ursodeoxycholic Acid (L-UDCA) Narrative (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Jun. 20, 2016	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Impairment of L-UDCA IPR&D intangible asset		$ 25,500	$ 25,500	$ 0	$ 0
Write off of L-UDCA contingent consideration		$ 18,000	$ 18,000	$ 0	$ 0
Economic Interest - L-UDCA (acquired IPR&D)
Business Acquisition [Line Items]
Intangible assets acquired with definite lives	$ 25,500
Assets useful life (in years)	17 years
Present value of contingent consideration	$ 25,000