Securities Held to Maturity (Summary of Amortized Cost, Unrealized Gains, Unrealized Losses and Estimated Fair Values) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	$ 97,589	$ 98,060
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	3,187
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	4,305	5
Debt Securities, Held-to-maturity, Fair Value	93,284	101,242
Tax Exempt State and Political Subdivisions General Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	71,458	71,807
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	2,583
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	2,834	0
Debt Securities, Held-to-maturity, Fair Value	68,624	74,390
Tax Exempt State and Political Subdivisions Water and Sewer Revenues [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	8,146	8,192
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	210
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	300	0
Debt Securities, Held-to-maturity, Fair Value	7,846	8,402
Tax Exempt State and Political Subdivisions Lease Revenues [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	4,295	4,316
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	74
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	314	0
Debt Securities, Held-to-maturity, Fair Value	3,981	4,390
Tax Exempt State and Political Subdivisions Sales Tax Revenues [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	4,566	4,582
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	106
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	282	0
Debt Securities, Held-to-maturity, Fair Value	4,284	4,688
Tax Exempt State and Political Subdivisions Various Tax Revenues
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	5,574
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	458
Debt Securities, Held-to-maturity, Fair Value	5,116
Tax Exempt State and Political Subdivisions Other Revenues [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	3,550	9,163
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	214
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	117	5
Debt Securities, Held-to-maturity, Fair Value	$ 3,433	$ 9,372