INCOME TAXES - Reconciliation of Unrecognized Income Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning balance	$ 8,651	$ 8,020	$ 6,599
Additions for tax positions of prior years	208	459	576
Additions for tax positions of current years	393	1,248	1,646
Expiration of the statute of limitations	(3,182)	(1,024)	(788)
Reductions for tax positions of prior years	(217)	(52)	(13)
Settlements	(805)	0	0
Unrecognized tax benefits, ending balance	$ 5,048	$ 8,651	$ 8,020