INCOME TAXES - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Rate applied to pretax income	$ 24,744	$ 31,916	$ 39,588
State taxes, net of federal benefit	5,147	6,427	4,060
Remeasurement of net deferred tax liabilities	0	0	(7,699)
Excess tax benefit on stock-based compensation	(833)	(6,685)	(6,009)
Other	(798)	489	(2,548)
Income taxes	$ 28,260	$ 32,147	$ 27,392
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Rate applied to pretax income	21.00%	21.00%	35.00%
State taxes, net of federal tax effect	4.40%	4.20%	3.60%
Remeasurement of net deferred tax liabilities	0.00%	0.00%	(6.80%)
Excess tax benefit on stock-based compensation	(0.70%)	(4.40%)	(5.30%)
Other	(0.70%)	0.40%	(2.30%)
Income taxes	24.00%	21.20%	24.20%