LEASES - Other Lease Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Weighted-average remaining lease term (years)
Operating leases	7 years 2 months 19 days		7 years 10 months 28 days
Finance leases	1 year 7 months 20 days		2 years 3 months 3 days
Weighted-average discount rate
Operating leases	7.90%		7.90%
Finance leases	6.00%		6.20%
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows for operating leases	$ 38,219	$ 38,018
Operating cash flows for finance leases	23	26
Financing cash flows for finance leases	$ 182	$ 175