SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Restructuring Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Restructuring Reserve [Roll Forward]
Charged to restructuring costs	$ 480	$ 1,238
Employee Termination Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	160
Charged to restructuring costs	0
Payments and adjustments	(160)
Balance at end of period	0
Lease-Related Exit Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	2,423
Charged to restructuring costs	389
Payments and adjustments	(192)
Balance at end of period	$ 2,620