Short-Term Borrowings and Long-Term Debt (Narrative) (Details)	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) loan
Debt Instrument [Line Items]
Long-term debt	$ 12,231,000	$ 27,302,000
Repayments of long-term debt		$ 10,000,000
Number of long-term fixed-rate advances added | loan		2
Early repayment of senior debt	15,000,000	$ 30,000,000
Debt prepayment fees	100,000
Debt conversion, original debt, amount	$ 200,000	$ 300,000
Percentage of Bank's long-term debt at fixed rate	1.89%	1.11%
Daily advances outstanding	$ 0	$ 0
Fixed Rate Convertible Advances, 0.79% and 0.43% Maturing in 2030
Debt Instrument [Line Items]
Proceeds from Issuance of debt		$ 27,000,000
Fixed Rate Convertible Advance, 0.79%, Maturing in 2030
Debt Instrument [Line Items]
Interest rate		0.79%
Fixed Rate Convertible Advance, 0.43% Maturing in 2030
Debt Instrument [Line Items]
Interest rate		0.43%
Fixed-Rate Convertible
Debt Instrument [Line Items]
Long-term debt	12,000,000
Letter of Credit
Debt Instrument [Line Items]
Line of credit facility, fair value of amount outstanding	63,000,000	$ 43,000,000
Other Commercial Banks
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	32,000,000	32,000,000
Credit Facility With Commercial Bank
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		40,000,000
Federal Home Loan Bank Borrowings
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	530,500,000	364,300,000
Security owned and pledged as collateral, fair value	723,100,000	542,600,000
FHLB lendable collateral	605,700,000	434,600,000
FHLB lendable pledged collateral	192,000,000	257,800,000
Line of credit facility, current borrowing capacity	116,800,000	187,500,000
Line of credit facility, fair value of amount outstanding	12,200,000	27,300,000
FHLB lendable unpledged collateral	413,700,000	176,800,000
Borrower in Custody | Federal Reserve Bank Of Richmond
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	3,300,000	6,000,000
Borrower in Custody or Unsecured and Secured Commercial Lines
Debt Instrument [Line Items]
Amount outstanding	$ 6,000,000	7,800,000
Maximum
Debt Instrument [Line Items]
Initial period after which debt callable	10 years
Minimum
Debt Instrument [Line Items]
Initial period after which debt callable	3 months
Advances and Security Agreement
Debt Instrument [Line Items]
Percentage of assets limited to maximum borrowing capacity	30.00%
Line of credit facility, maximum borrowing capacity	$ 697,800,000	$ 607,400,000