Loans and Related Allowance for Loan Losses (Summary of Financial Receivable Impaired Average Recorded Investment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Average Investment	$ 8,607	$ 13,080	$ 9,198	$ 15,166
Interest Recognized	59	64	175	190
Mortgage Loans on Real Estate [Member]
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Average Investment	7,174	11,994	7,956	13,543
Interest Recognized	56	60	166	177
Commercial Loans [Member]
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Average Investment	1,418	1,080	1,230	1,618
Interest Recognized	3	4	9	13
Consumer Installment Loans [Member]
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Average Investment	15	6	12	5
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Average Investment	3,044	3,376	3,028	3,499
Interest Recognized	20	23	59	68
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Average Investment	3,232	3,860	3,324	4,219
Interest Recognized	36	37	107	109
Construction and Land Development [Member] | Mortgage Loans on Real Estate [Member]
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Average Investment	847	2,248	962	3,292
Multifamily [Member] | Mortgage Loans on Real Estate [Member]
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Average Investment		$ 2,510	616	$ 2,533
Agriculture [Member] | Mortgage Loans on Real Estate [Member]
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Average Investment	$ 51		$ 26