INCOME TAXES - Income Tax Uncertainties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of period	$ 4,762	$ 5,709	$ 4,781
Increases for tax positions of prior years	267	431	1,366
Decreases for tax positions of prior years	(391)	(1,978)	(1,185)
Increases for tax positions related to current year	697	600	747
Balance at end of period	$ 5,335	$ 4,762	$ 5,709