Income Taxes - Income Tax Expense (Benefit) Included in Consolidated Statements of Comprehensive Income (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
Current:
Federal									$ 21,926	$ 12,776	$ 12,626
Foreign									78	48	45
State and local									5,584	4,110	2,808
Total									27,588	16,934	15,479
Deferred:
Federal									(1,968)	3,685	2,047
State and local									(479)	1,221	741
Total									(2,447)	4,906	2,788
Total income tax expense from continuing operations	$ (1,979)	$ 7,060	$ 6,607	$ 13,453	$ (3,164)	$ 6,069	$ 5,322	$ 13,613	25,141	21,840	18,267
Operations of discontinued operations:
Current									(11)	(107)	2
Deferred									0	(1)	(1)
Total income tax expense from discontinued    operations									(11)	(108)	1
Total income tax expense									$ 25,130	$ 21,732	$ 18,268