RESTRUCTURING CHARGES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Severance and benefit costs	$ 876	$ 15,705
Other exit costs	213	2,101
Restructuring liability	$ 828	8,744	$ 3,763
December 2020 Plan
Restructuring Cost and Reserve [Line Items]
Severance and benefit costs		9,600
Other exit costs		1,600
Write-off of fixed assets		900
Loss on early lease terminations		700
Restructuring liability		7,200
Zyla Merger Reorganization
Restructuring Cost and Reserve [Line Items]
Severance and benefit costs		5,600
Other exit costs		200
Severance costs, share-based compensation		1,000
Restructuring liability		700
Reduction In Workforce Due To COVID-19
Restructuring Cost and Reserve [Line Items]
Severance and benefit costs		300
Other exit costs		300
2019 Plan
Restructuring Cost and Reserve [Line Items]
Severance and benefit costs		200
Restructuring liability		$ 800