Allowance for loan losses and credit quality Troubled Debt Restured Loans (Details) $ in Thousands	Sep. 30, 2020 USD ($) loan	Dec. 31, 2019 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan	47	40
Principal Balance \| $	$ 3,053	$ 2,871
Residential real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan	32	25
Principal Balance \| $	$ 1,805	$ 1,515
Construction real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan	2	2
Principal Balance \| $	$ 89	$ 100
Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan	8	8
Principal Balance \| $	$ 930	$ 966
Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan	5	5
Principal Balance \| $	$ 229	$ 290

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

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Amount of financing receivable modified as troubled debt restructuring.

+ 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

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-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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