Income Taxes (Schedule of Effective Income Tax Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Tax at statutory rate	$ 47,186	$ 46,600	$ 47,015
State income taxes, net of federal tax benefits	8,580	8,575	8,098
Non-deductible meals and entertainment	903	1,117	1,044
Income tax credits	(1,200)	(1,600)	(1,800)
Equity compensation	(821)	(207)	(312)
Other, net	968	477	1,688
Total income tax expense (benefit)	$ 55,616	$ 54,962	$ 55,733