Income Taxes (Reconciliation Of The Significant Differences Between The Federal Statutory Income Tax Rate And Effective Income Tax Rate) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Computed federal taxes at statutory rate									$ 23,832	$ 18,483	$ 31,761
State income taxes, net of federal tax benefit									2,376	1,730	1,321
Tax effects of:
Tax-exempt interest income									(733)	(694)	(1,098)
Bank-owned life insurance									(791)	(649)	(1,474)
Change in statutory tax rate									0	0	7,070
Other items, net									(549)	(855)	(1,145)
Income tax expense	$ 6,319	$ 6,193	$ 5,813	$ 5,810	$ 2,646	$ 5,606	$ 5,358	$ 4,405	$ 24,135	$ 18,015	$ 36,435