Summary of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) operation_center loan branch loan_production_office	Dec. 31, 2020 USD ($) loan	Jan. 01, 2022 USD ($)
Property, Plant and Equipment [Line Items]
Number of operation centers | operation_center	2
Number of LPOs | loan_production_office	4
Trading securities	$ 0	$ 0
Loans held for sale	$ 0	0
Number of mortgage loans sold | loan	28
Fair value of mortgage banking derivatives	$ 4,772,000	4,855,000
Occupancy expense, depreciation of premises and equipment and other	1,500,000	1,600,000
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 7,574,000	$ 18,222,000
Total TDRs | loan	1	6
Interest Rate Lock Commitments
Property, Plant and Equipment [Line Items]
Derivative asset	$ 28,000	$ 0
Net gain on mortgage related banking derivatives	28,000	0
Substandard
Property, Plant and Equipment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 3,900,000
Total TDRs | loan	4
Other Assets | Interest Rate Lock Commitments
Property, Plant and Equipment [Line Items]
Derivative notional value	$ 1,200,000	$ 0
Gross U.S. Small Business Administration ("SBA") Paycheck Protection Program ("PPP") loans
Property, Plant and Equipment [Line Items]
Percentage status of loan in portfolio	1.70%	89.39%
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 57,000
Nonperforming Financial Instruments | Substandard
Property, Plant and Equipment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	100,000	$ 3,400,000
Nonperforming Financial Instruments | Gross U.S. Small Business Administration ("SBA") Paycheck Protection Program ("PPP") loans
Property, Plant and Equipment [Line Items]
Loans deferred, original loan amount	0	$ 35,400,000
Performing Financial Instruments | Substandard
Property, Plant and Equipment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 3,800,000
Maryland and Virginia
Property, Plant and Equipment [Line Items]
Number of branches | branch	11
Leonardtown, La Plata
Property, Plant and Equipment [Line Items]
Number of branches | branch	2
Maximum | Executed Modifications, COVID-19 Loan Modification Program, Executed Modifications | Receivables Under Coronavirus Aid, Relief and Economic Security, Act. | Payment Deferral
Property, Plant and Equipment [Line Items]
Loan deferral, period		180 days
Maximum | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment | Forecast
Property, Plant and Equipment [Line Items]
Allowance for credit loss			$ 3,000,000
Minimum | Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment | Forecast
Property, Plant and Equipment [Line Items]
Allowance for credit loss			$ 2,000,000
Building and Building Improvements | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	50 years
Building and Building Improvements | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	10 years
Furniture and Fixtures | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	15 years
Furniture and Fixtures | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Automobiles | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Automobiles | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	4 years