LEASES - SUMMARY OF RIGHT OF USE ASSETS AND LEASE LIABILITIES (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Right-of-use assets	$ 1,075	$ 1,607
Liabilities
Operating lease liabilities - current	1,213	1,382
Operating lease liabilities - long-term	795	1,677
Total lease liabilities	$ 2,008	$ 3,059