REVENUE - Summary of Contract Assets and Liabilities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Contract With Customer, Asset [Roll Forward]
Contract asset, Beginning of Period	$ 0
Additions	60,705
Deductions	(58,289)
Contract asset, End of Period	2,416
Contract asset, net - Collegium
Contract With Customer, Asset [Roll Forward]
Contract asset, Beginning of Period	0
Additions	55,705
Deductions	(53,289)
Contract asset, End of Period	2,416
Contract asset - Ironwood
Contract With Customer, Asset [Roll Forward]
Contract asset, Beginning of Period	0
Additions	5,000
Deductions	(5,000)
Contract asset, End of Period	$ 0