ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Product Shipments and Accounts Receivable, By Distributor (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Customer concentration risk | Consolidated revenue
Concentration Risk [Line Items]
Total	100.00%	100.00%
Credit concentration risk | Accounts receivable related to product sales
Concentration Risk [Line Items]
Total	100.00%	100.00%
Cardinal Health | Customer concentration risk | Consolidated revenue
Concentration Risk [Line Items]
Total	42.00%	10.00%
Cardinal Health | Credit concentration risk | Accounts receivable related to product sales
Concentration Risk [Line Items]
Total	53.00%	25.00%
McKesson Corporation | Customer concentration risk | Consolidated revenue
Concentration Risk [Line Items]
Total	14.00%	16.00%
McKesson Corporation | Credit concentration risk | Accounts receivable related to product sales
Concentration Risk [Line Items]
Total	20.00%	46.00%
AmerisourceBergen Corporation | Customer concentration risk | Consolidated revenue
Concentration Risk [Line Items]
Total	13.00%	12.00%
AmerisourceBergen Corporation | Credit concentration risk | Accounts receivable related to product sales
Concentration Risk [Line Items]
Total	18.00%	17.00%
Collegium | Customer concentration risk | Consolidated revenue
Concentration Risk [Line Items]
Total	11.00%	52.00%
Collegium | Credit concentration risk | Accounts receivable related to product sales
Concentration Risk [Line Items]
Total	0.00%	0.00%
All others | Customer concentration risk | Consolidated revenue
Concentration Risk [Line Items]
Total	20.00%	10.00%
All others | Credit concentration risk | Accounts receivable related to product sales
Concentration Risk [Line Items]
Total	9.00%	12.00%