COST OF REVENUE - Schedule of Components (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Cost of Revenue [Abstract]
Outside fees and services	$ 13,659	$ 15,319	$ 42,810	$ 42,573
Compensation and benefits	9,090	11,885	28,072	39,231
Technology and telecommunications	3,786	4,656	11,048	14,844
Reimbursable expenses	2,039	1,957	6,398	6,158
Depreciation and amortization	450	570	1,356	1,805
Total	$ 29,024	$ 34,387	$ 89,684	$ 104,611