REVENUE RECOGNITION (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 51,139	$ 44,373	$ 147,338	$ 128,651
Bile acid products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	22,912	19,938	66,766	59,258
Tiopronin products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 28,227	$ 24,435	$ 80,572	$ 69,393
Geographic Concentration Risk | Revenue from Contract with Customer | North America
Disaggregation of Revenue [Line Items]
Concentration risk, percentage			95.00%