Securities (Summary Of Securities Available For Sale In Unrealized Loss Position) (Details) $ in Thousands	Dec. 31, 2018 USD ($) security	Dec. 31, 2017 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	134	82
Less than 12 months, Estimated Fair Value		$ 65,199
Less than 12 months, Unrealized Loss		550
12 months or more, Estimated Fair Value		37,384
12 months or more, Unrealized Loss		964
Debt Securities, Available-for-sale, Unrealized Loss Position		102,583
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 1,514
Temporarily Impaired Securities Member
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	134	82
Less than 12 months, Estimated Fair Value	$ 75,442	$ 65,199
Less than 12 months, Unrealized Loss	791	550
12 months or more, Estimated Fair Value	84,860	37,384
12 months or more, Unrealized Loss	2,220	964
Debt Securities, Available-for-sale, Unrealized Loss Position	160,302	102,583
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 3,011	$ 1,514
Temporarily Impaired Securities Member | 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	9
Less than 12 months, Estimated Fair Value	$ 12,185	$ 10,864
Less than 12 months, Unrealized Loss	184	91
12 months or more, Estimated Fair Value	7,464	2,394
12 months or more, Unrealized Loss	182	54
Debt Securities, Available-for-sale, Unrealized Loss Position	19,649	13,258
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 366	$ 145
Temporarily Impaired Securities Member | Government-sponsored agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	37	35
Less than 12 months, Estimated Fair Value	$ 23,277	$ 32,156
Less than 12 months, Unrealized Loss	241	269
12 months or more, Estimated Fair Value	24,472	22,584
12 months or more, Unrealized Loss	936	634
Debt Securities, Available-for-sale, Unrealized Loss Position	47,749	54,740
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 1,177	$ 903
Temporarily Impaired Securities Member | Nongovernment-sponsored entities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	1	1
Less than 12 months, Estimated Fair Value	$ 0	$ 5
Less than 12 months, Unrealized Loss	0	0
12 months or more, Estimated Fair Value	436	810
12 months or more, Unrealized Loss	1	7
Debt Securities, Available-for-sale, Unrealized Loss Position	436	815
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 1	$ 7
Temporarily Impaired Securities Member | 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	8	9
Less than 12 months, Estimated Fair Value	$ 0	$ 6,035
Less than 12 months, Unrealized Loss	0	55
12 months or more, Estimated Fair Value	5,222	0
12 months or more, Unrealized Loss	126	0
Debt Securities, Available-for-sale, Unrealized Loss Position	5,222	6,035
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 126	$ 55
Temporarily Impaired Securities Member | 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	11	9
Less than 12 months, Estimated Fair Value	$ 968	$ 7,532
Less than 12 months, Unrealized Loss	16	62
12 months or more, Estimated Fair Value	9,450	0
12 months or more, Unrealized Loss	170	0
Debt Securities, Available-for-sale, Unrealized Loss Position	10,418	7,532
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 186	$ 62
Temporarily Impaired Securities Member | Corporate debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	7	4
Less than 12 months, Estimated Fair Value	$ 2,759	$ 3,008
Less than 12 months, Unrealized Loss	109	39
12 months or more, Estimated Fair Value	4,587	1,659
12 months or more, Unrealized Loss	195	91
Debt Securities, Available-for-sale, Unrealized Loss Position	7,346	4,667
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 304	$ 130
Temporarily Impaired Securities Member | Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	9
Less than 12 months, Estimated Fair Value	$ 20,129
Less than 12 months, Unrealized Loss	123
12 months or more, Estimated Fair Value	0
12 months or more, Unrealized Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position	20,129
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 123
Temporarily Impaired Securities Member | 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	12
Less than 12 months, Estimated Fair Value	$ 7,273	$ 2,999
Less than 12 months, Unrealized Loss	50	20
12 months or more, Estimated Fair Value	16,830	9,937
12 months or more, Unrealized Loss	294	178
Debt Securities, Available-for-sale, Unrealized Loss Position	24,103	12,936
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 344	$ 198
Temporarily Impaired Securities Member | 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	1
Less than 12 months, Estimated Fair Value	$ 989	$ 282
Less than 12 months, Unrealized Loss	6	3
12 months or more, Estimated Fair Value	4,311	0
12 months or more, Unrealized Loss	92	0
Debt Securities, Available-for-sale, Unrealized Loss Position	5,300	282
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 98	$ 3
Temporarily Impaired Securities Member | 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	1
Less than 12 months, Estimated Fair Value	$ 553	$ 569
Less than 12 months, Unrealized Loss	0	2
12 months or more, Estimated Fair Value	557	0
12 months or more, Unrealized Loss	7	0
Debt Securities, Available-for-sale, Unrealized Loss Position	1,110	569
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 7	$ 2
Temporarily Impaired Securities Member | Tax Exempt 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		$ 1,749
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		1,749
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 9
Temporarily Impaired Securities Member | 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	12
Less than 12 months, Estimated Fair Value	$ 7,309
Less than 12 months, Unrealized Loss	62
12 months or more, Estimated Fair Value	11,531
12 months or more, Unrealized Loss	217
Debt Securities, Available-for-sale, Unrealized Loss Position	18,840
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 279