INTANGIBLE ASSETS - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Jun. 30, 2016
Finite-Lived Intangible Assets [Line Items]
Net book value of amortizable intangible assets	$ 157,799			$ 157,799		$ 186,691
Impairment of L-UDCA IPR&D intangible asset	0	$ 25,500	$ 0	25,500	$ 0
IPR&D asset	$ 241,195			$ 241,195		255,643
Acquired Product Rights L-UDCA
Finite-Lived Intangible Assets [Line Items]
Impairment of L-UDCA IPR&D intangible asset		$ 25,500
IPR&D asset						$ 25,500	$ 25,500