INCOME TAXES - Uncertain Tax Position (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 1,161	$ 1,158	$ 0
Gross increases in tax positions in current period	0	2	0
Gross increase in tax positions in prior period	38	37	32
Gross decrease in tax positions in prior period	0	(1)	(1)
Gross increase in tax positions from acquisitions	0	16	1,162
Lapse of statute of limitations	(416)	(51)	(35)
Ending balance	$ 783	$ 1,161	$ 1,158