Securities (Summary Of Securities Available For Sale In Unrealized Loss Position) (Details) $ in Thousands	Dec. 31, 2020 USD ($) security	Dec. 31, 2019 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	78	88
Less than 12 months, Estimated Fair Value	$ 30,171	$ 53,992
Less than 12 months, Unrealized Loss	(155)	(668)
12 months or more, Estimated Fair Value	59,645	63,389
12 months or more, Unrealized Loss	(1,590)	(1,647)
Debt Securities, Available-for-sale, Unrealized Loss Position	89,816	117,381
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 1,745	$ 2,315
U.S. Government and agencies and corporations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	36	15
Less than 12 months, Estimated Fair Value	$ 12,611	$ 0
Less than 12 months, Unrealized Loss	(54)	0
12 months or more, Estimated Fair Value	14,384	14,903
12 months or more, Unrealized Loss	(340)	(384)
Debt Securities, Available-for-sale, Unrealized Loss Position	26,995	14,903
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 394	$ 384
Government-sponsored agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	10	21
Less than 12 months, Estimated Fair Value	$ 3,127	$ 12,298
Less than 12 months, Unrealized Loss	(34)	(96)
12 months or more, Estimated Fair Value	8,593	15,174
12 months or more, Unrealized Loss	(315)	(339)
Debt Securities, Available-for-sale, Unrealized Loss Position	11,720	27,472
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 349	$ 435
Nongovernment-sponsored entities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	6	4
Less than 12 months, Estimated Fair Value	$ 6,770	$ 8,323
Less than 12 months, Unrealized Loss	(35)	(41)
12 months or more, Estimated Fair Value	2,751	0
12 months or more, Unrealized Loss	(209)	0
Debt Securities, Available-for-sale, Unrealized Loss Position	9,521	8,323
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 244	$ 41
State and Political Subdivisions General Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	1	10
Less than 12 months, Estimated Fair Value	$ 362	$ 10,581
Less than 12 months, Unrealized Loss	(4)	(171)
12 months or more, Estimated Fair Value	0	0
12 months or more, Unrealized Loss	0	0
Debt Securities, Available-for-sale, Unrealized Loss Position	362	10,581
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 4	$ 171
State and Political Subdivisions Lease Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security		4
Less than 12 months, Estimated Fair Value		$ 4,235
Less than 12 months, Unrealized Loss		(77)
12 months or more, Estimated Fair Value		0
12 months or more, Unrealized Loss		0
Debt Securities, Available-for-sale, Unrealized Loss Position		4,235
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 77
State and Political Subdivisions University Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security		1
Less than 12 months, Estimated Fair Value		$ 1,307
Less than 12 months, Unrealized Loss		(16)
12 months or more, Estimated Fair Value		0
12 months or more, Unrealized Loss		0
Debt Securities, Available-for-sale, Unrealized Loss Position		1,307
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 16
State and political subdivisions, Other revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security		6
Less than 12 months, Estimated Fair Value		$ 6,517
Less than 12 months, Unrealized Loss		(109)
12 months or more, Estimated Fair Value		0
12 months or more, Unrealized Loss		0
Debt Securities, Available-for-sale, Unrealized Loss Position		6,517
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 109
Corporate debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	6	6
Less than 12 months, Estimated Fair Value	$ 3,952	$ 1,686
Less than 12 months, Unrealized Loss	(16)	(3)
12 months or more, Estimated Fair Value	1,904	3,739
12 months or more, Unrealized Loss	(96)	(146)
Debt Securities, Available-for-sale, Unrealized Loss Position	5,856	5,425
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 112	$ 149
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	16	15
Less than 12 months, Estimated Fair Value	$ 2,010	$ 3,441
Less than 12 months, Unrealized Loss	(2)	(34)
12 months or more, Estimated Fair Value	31,862	29,573
12 months or more, Unrealized Loss	(623)	(778)
Debt Securities, Available-for-sale, Unrealized Loss Position	33,872	33,014
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 625	$ 812
Tax Exempt State and Political Subdivisions General Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	1
Less than 12 months, Estimated Fair Value	$ 924
Less than 12 months, Unrealized Loss	(9)
12 months or more, Estimated Fair Value	0
12 months or more, Unrealized Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position	924
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 9
Tax Exempt State and Political Subdivisions Other Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	2	2
Less than 12 months, Estimated Fair Value	$ 415	$ 1,183
Less than 12 months, Unrealized Loss	(1)	(7)
12 months or more, Estimated Fair Value	151	0
12 months or more, Unrealized Loss	(7)	0
Debt Securities, Available-for-sale, Unrealized Loss Position	566	1,183
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 8	$ 7
State and Policital Subdivisions Water and Sewer Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security		4
Less than 12 months, Estimated Fair Value		$ 4,421
Less than 12 months, Unrealized Loss		(114)
12 months or more, Estimated Fair Value		0
12 months or more, Unrealized Loss		0
Debt Securities, Available-for-sale, Unrealized Loss Position		4,421
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 114