Allowance for loan losses and credit quality New Troubled Debt Restructure Loans (Details) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($) loans	Dec. 31, 2015 USD ($) loans
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructured Loans, Number of Loans \| loans	9	6
New Troubled Debt Restructured Loans, Pre-Modification Recorded Investment	$ 349	$ 590
New Troubled Debt Restructured Loans, Post-Modification Recorded Investment	$ 371	$ 597
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructured Loans, Number of Loans \| loans	6	2
New Troubled Debt Restructured Loans, Pre-Modification Recorded Investment	$ 803	$ 281
New Troubled Debt Restructured Loans, Post-Modification Recorded Investment	$ 807	$ 281
Commercial [Member]
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructured Loans, Number of Loans \| loans	0	2
New Troubled Debt Restructured Loans, Pre-Modification Recorded Investment	$ 0	$ 493
New Troubled Debt Restructured Loans, Post-Modification Recorded Investment	$ 0	$ 493

Number of financing receivables that have been modified by troubled debt restructurings during the reporting period.

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+ References

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Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953676-111524

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Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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