Income Taxes and Related Payments - Components of provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	$ 24,116	$ 13,609	$ 18,247
State and local	8,174	6,315	3,993
Foreign	515	529	495
Total	32,805	20,453	22,735
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	27,110	22,310	22,218
State and local	880	(14,954)	2,645
Total	27,990	7,356	24,863
Income tax expense	$ 60,795	$ 27,809	$ 47,598

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

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Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

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Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

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