INCOME TAXES - Current and deferred amounts of income tax expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Current	$ 14,967	$ 10,952	$ 12,708
Deferred	(1,521)	4,430	(3,337)
Adjustment to the net deferred tax asset for the Tax Cuts and Jobs Act	0	885	0
Income tax expense	$ 13,446	$ 16,267	$ 9,371