Securities (Summary Of Amortized Cost, Unrealized Gains, Unrealized Losses And Estimated Fair Values) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	$ 277,157	$ 272,215
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	10,715	6,455
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1,745	2,315
Debt Securities, Available-for-sale	286,127	276,355
U.S. Government and agencies and corporations [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	35,190	21,036
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	361	212
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	394	384
Debt Securities, Available-for-sale	35,157	20,864
Government-sponsored agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	57,399	70,379
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1,996	1,031
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	349	435
Debt Securities, Available-for-sale	59,046	70,975
Nongovernment-sponsored entities [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	16,799	10,253
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	132	17
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	244	41
Debt Securities, Available-for-sale	16,687	10,229
State and Political Subdivisions General Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	15,065	12,603
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	804	25
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	4	171
Debt Securities, Available-for-sale	15,865	12,457
State and Policital Subdivisions Water and Sewer Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	10,176	7,170
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	620	71
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	114
Debt Securities, Available-for-sale	10,796	7,127
State and Political Subdivisions Lease Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	4,825	5,310
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	341	25
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	77
Debt Securities, Available-for-sale	5,166	5,258
State and Political Subdivisions University Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	3,022	5,917
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	315	164
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	16
Debt Securities, Available-for-sale	3,337	6,065
State and policital subdivisions, Other revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	9,406	18,831
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	907	344
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	109
Debt Securities, Available-for-sale	10,313	19,066
Corporate debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	26,483	18,268
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	56	81
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	112	149
Debt Securities, Available-for-sale	26,427	18,200
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	46,579	33,826
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	172	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	625	812
Debt Securities, Available-for-sale	46,126	33,014
Total taxable debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	229,996	203,593
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	6,080	1,970
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1,728	2,308
Debt Securities, Available-for-sale	234,348	203,255
Tax Exempt State and Political Subdivisions General Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	22,213	36,673
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	2,416	2,526
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	9	0
Debt Securities, Available-for-sale	24,620	39,199
Tax Exempt State and Political Subdivisions Water and Sewer Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	8,266	9,565
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	709	633
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale	8,975	10,198
Tax Exempt State and Political Subdivisions Lease Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	7,195	8,455
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	799	598
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale	7,994	9,053
Tax Exempt State and Political Subdivisions Other Revenues [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	9,487	13,929
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	711	728
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	8	7
Debt Securities, Available-for-sale	10,190	14,650
Total tax-exempt debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	47,161	68,622
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	4,635	4,485
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	17	7
Debt Securities, Available-for-sale	51,779	$ 73,100
State and Political Subdivisions Income Tax Revenues [Domain]
Debt Securities, Available-for-sale [Line Items]
Total Amortized Cost	5,052
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	376
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0
Debt Securities, Available-for-sale	$ 5,428