Loans and Allowance for Credit Losses on Loans (Summary of All Troubled Debt Restructuring Loans (Accruing and Non Accruing) by Portfolio Segment) (Details)	12 Months Ended
Dec. 31, 2020 USD ($) loan	Dec. 31, 2019 USD ($) loan	Dec. 31, 2018 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	25	27
Recorded Investment	$ 3,066,000	$ 3,629,000
Specific Reserve	$ 401,000	$ 463,000
Number of Contracts	0	2	3
Pre-Modification Outstanding Recorded Investment	$ 0	$ 64,000	$ 397,000
Post-Modification Outstanding Recorded Investment	0	69,000	420,000
Specific Reserve	$ 0	$ 15,000	95,000
Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	2	2
Recorded Investment	$ 328,000	$ 338,000
Specific Reserve	$ 37,000	$ 30,000
Commercial
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	2	2
Recorded Investment	$ 100,000	$ 123,000
Specific Reserve	$ 0	$ 0
Home equity
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	0	1
Recorded Investment	$ 0	$ 299,000
Specific Reserve	$ 0	$ 69,000
Residential real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	21	22
Recorded Investment	$ 2,638,000	$ 2,869,000
Specific Reserve	$ 364,000	$ 364,000
Home Equity Loan
Financing Receivable, Modifications [Line Items]
Specific Reserve			$ 162,000
Interest Rate and Maturity Concession \| Residential real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	0	2	2
Pre-Modification Outstanding Recorded Investment	$ 0	$ 64,000	$ 231,000
Post-Modification Outstanding Recorded Investment	0	69,000	254,000
Specific Reserve	$ 0	$ 15,000	$ 50,000
Payment Deferral \| Residential real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	0	0	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 166,000
Post-Modification Outstanding Recorded Investment	0	0	166,000
Specific Reserve	$ 0	$ 0	$ 45,000

Allowance for Credit Losses, Related to Troubled Debt Restructured Loans

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Allowance Related to Troubled Debt Restructurings assigned during period

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Financing Receivable Modifications Number Of Contracts Outstanding

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

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