INCOME TAXES - Reconciliation of Income Tax Provision To Total Income Taxes At Statutory Federal Tax Rate (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
Income Taxes
Federal income taxes, at statutory tax rate									$ 15,378	$ 23,663	$ 18,619
State income taxes, net of federal benefit									3,987	6,977	5,157
Nondeductible expenses									365	651	454
Tax credits									(2,093)
Other, net									(206)	(723)	(158)
Income tax provision	$ 4,505	$ 4,130	$ 2,950	$ 5,846	$ 7,900	$ 8,949	$ 8,839	$ 4,880	$ 17,431	$ 30,568	$ 24,072