Loans, Allowance for Loan Losses and Credit Quality - Summary of Average Recorded Investment and Interest Income recognized on Impaired Loans (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Financing Receivable Impaired [Line Items]
Impaired loans, Average recorded investment	$ 4,602	$ 3,910
Impaired loans, Ending recorded investment	4,081	3,889	$ 5,099
Impaired loans, Interest income	60	68
Home Equity Lines of Credit
Financing Receivable Impaired [Line Items]
Impaired loans, Average recorded investment	372	314
Impaired loans, Ending recorded investment	301	314	408
Impaired loans, Interest income	4	3
Commercial Loans
Financing Receivable Impaired [Line Items]
Impaired loans, Average recorded investment	291	409
Impaired loans, Ending recorded investment	286	406	294
Impaired loans, Interest income	4	9
Consumer Loans
Financing Receivable Impaired [Line Items]
Impaired loans, Average recorded investment	77
Impaired loans, Ending recorded investment	71		82
Mortgage Loans on Real Estate
Financing Receivable Impaired [Line Items]
Impaired loans, Average recorded investment	3,862	3,187
Impaired loans, Ending recorded investment	3,423	3,169	4,315
Impaired loans, Interest income	52	56
Mortgage Loans on Real Estate \| Residential Real Estate
Financing Receivable Impaired [Line Items]
Impaired loans, Average recorded investment	843	638
Impaired loans, Ending recorded investment	773	582	799
Impaired loans, Interest income	6	7
Mortgage Loans on Real Estate \| Commercial Real Estate
Financing Receivable Impaired [Line Items]
Impaired loans, Average recorded investment	2,786	2,406
Impaired loans, Ending recorded investment	2,650	2,447	3,084
Impaired loans, Interest income	46	45
Mortgage Loans on Real Estate \| Construction and Land Development
Financing Receivable Impaired [Line Items]
Impaired loans, Average recorded investment	$ 233	143
Impaired loans, Ending recorded investment		140	$ 432
Impaired loans, Interest income		$ 4

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953550-111524

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