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, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Computed federal taxes at statutory rate									$ 18,483	$ 31,761	$ 27,025
State income taxes, net of federal tax benefit									1,730	1,321	888
Tax effects of:
Tax-exempt interest income									(694)	(1,098)	(708)
Bank-owned life insurance									(649)	(1,474)	(1,164)
Change in statutory tax rate									0	7,070	0
Other items, net									(855)	(1,145)	(958)
Income tax expense	$ 2,646	$ 5,606	$ 5,358	$ 4,405	$ 14,972	$ 7,003	$ 6,812	$ 7,647	$ 18,015	$ 36,435	$ 25,083