INCOME TAXES - Reconciliation of provision for income taxes from continuing operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
"Expected" provision at federal statutory rate									$ 11,046	$ 9,654	$ 10,286
State income taxes, net									2,408	1,540	2,029
Change in valuation allowance									(422)	(168)	1,304
Compensation limits									125	148	0
Federal and state tax credits									(1,035)	(1,302)	(807)
Other									78	149	85
Total	$ 3,620	$ 2,862	$ 2,550	$ 3,224	$ 2,936	$ 3,025	$ 2,642	$ (1,459)	$ 12,256	$ 7,144	$ 11,696
Effective tax rate									23.30%	15.60%	23.90%
Federal
Operating Loss Carryforwards [Line Items]
Share-based compensation									$ 56	$ (2,877)	$ (1,201)