Securities (Summary Of Securities Available For Sale In Unrealized Loss Position) (Details) $ in Thousands	Dec. 31, 2019 USD ($) security	Dec. 31, 2018 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	88	134
Less than 12 months, Estimated Fair Value	$ 53,992	$ 75,442
Less than 12 months, Unrealized Loss	(668)	(791)
12 months or more, Estimated Fair Value	63,389	84,860
12 months or more, Unrealized Loss	(1,647)	(2,220)
Debt Securities, Available-for-sale, Unrealized Loss Position	117,381	160,302
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 2,315	$ 3,011
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	15	15
Less than 12 months, Estimated Fair Value	$ 0	$ 12,185
Less than 12 months, Unrealized Loss	0	(184)
12 months or more, Estimated Fair Value	14,903	7,464
12 months or more, Unrealized Loss	(384)	(182)
Debt Securities, Available-for-sale, Unrealized Loss Position	14,903	19,649
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 384	$ 366
Government-sponsored agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	21	37
Less than 12 months, Estimated Fair Value	$ 12,298	$ 23,277
Less than 12 months, Unrealized Loss	(96)	(241)
12 months or more, Estimated Fair Value	15,174	24,472
12 months or more, Unrealized Loss	(339)	(936)
Debt Securities, Available-for-sale, Unrealized Loss Position	27,472	47,749
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 435	$ 1,177
Nongovernment-sponsored entities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	4	1
Less than 12 months, Estimated Fair Value	$ 8,323	$ 0
Less than 12 months, Unrealized Loss	(41)	0
12 months or more, Estimated Fair Value	0	436
12 months or more, Unrealized Loss	0	(1)
Debt Securities, Available-for-sale, Unrealized Loss Position	8,323	436
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 41	$ 1
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	10	8
Less than 12 months, Estimated Fair Value	$ 10,581	$ 0
Less than 12 months, Unrealized Loss	(171)	0
12 months or more, Estimated Fair Value	0	5,222
12 months or more, Unrealized Loss	0	(126)
Debt Securities, Available-for-sale, Unrealized Loss Position	10,581	5,222
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 171	$ 126
State and Political 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
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	11
Less than 12 months, Estimated Fair Value	$ 6,517	$ 968
Less than 12 months, Unrealized Loss	(109)	(16)
12 months or more, Estimated Fair Value	0	9,450
12 months or more, Unrealized Loss	0	(170)
Debt Securities, Available-for-sale, Unrealized Loss Position	6,517	10,418
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 109	$ 186
Corporate debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	6	7
Less than 12 months, Estimated Fair Value	$ 1,686	$ 2,759
Less than 12 months, Unrealized Loss	(3)	(109)
12 months or more, Estimated Fair Value	3,739	4,587
12 months or more, Unrealized Loss	(146)	(195)
Debt Securities, Available-for-sale, Unrealized Loss Position	5,425	7,346
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 149	$ 304
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	15	9
Less than 12 months, Estimated Fair Value	$ 3,441	$ 20,129
Less than 12 months, Unrealized Loss	(34)	(123)
12 months or more, Estimated Fair Value	29,573	0
12 months or more, Unrealized Loss	(778)	0
Debt Securities, Available-for-sale, Unrealized Loss Position	33,014	20,129
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 812	$ 123
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		25
Less than 12 months, Estimated Fair Value		$ 7,273
Less than 12 months, Unrealized Loss		(50)
12 months or more, Estimated Fair Value		16,830
12 months or more, Unrealized Loss		(294)
Debt Securities, Available-for-sale, Unrealized Loss Position		24,103
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 344
Tax Exempt State and Political 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		7
Less than 12 months, Estimated Fair Value		$ 989
Less than 12 months, Unrealized Loss		(6)
12 months or more, Estimated Fair Value		4,311
12 months or more, Unrealized Loss		(92)
Debt Securities, Available-for-sale, Unrealized Loss Position		5,300
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 98
Tax Exempt 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		2
Less than 12 months, Estimated Fair Value		$ 553
Less than 12 months, Unrealized Loss		0
12 months or more, Estimated Fair Value		557
12 months or more, Unrealized Loss		(7)
Debt Securities, Available-for-sale, Unrealized Loss Position		1,110
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 7
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	12
Less than 12 months, Estimated Fair Value	$ 1,183	$ 7,309
Less than 12 months, Unrealized Loss	(7)	(62)
12 months or more, Estimated Fair Value	0	11,531
12 months or more, Unrealized Loss	0	(217)
Debt Securities, Available-for-sale, Unrealized Loss Position	1,183	18,840
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 7	$ 279