LEASES - Supplemental cash flow information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows from operating leases	$ 3,057	$ 3,081
Operating cash outflows from finance leases	15	33
Financing cash outflows from finance leases	1,970	2,500
ROU assets obtained in exchange for lease obligations:
Finance leases	2,767	2,231
Operating leases	$ 251	$ 2,117