Allowance for loan losses and credit quality New Troubled Debt Restructured Loans (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2015 USD ($) loans	Sep. 30, 2014 USD ($) loans	Sep. 30, 2015 USD ($) loans	Sep. 30, 2014 USD ($) loans
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructured Loans, Number of Loans \| loans	5	1	5	1
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 504	$ 325	$ 504	$ 325
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 511	$ 325	$ 511	$ 325
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructured Loans, Number of Loans \| loans	0	0	2	2
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0	$ 0	$ 281	$ 1,018
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 0	$ 281	$ 1,068

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

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

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

+ Details

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- Definition

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

+ References

+ Details

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