Allowance for Loan Losses and Credit Quality of Loans, Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016 USD ($) Contract	Jun. 30, 2015 USD ($) Contract	Jun. 30, 2016 USD ($) Contract	Jun. 30, 2015 USD ($) Contract
Financing Receivable, Modifications [Line Items]
Period of sustained repayment performance for nonperforming TDRs to be returned to performing status			6 months
Number of contracts \| Contract	4	20	20	48
Pre-modification outstanding recorded investment	$ 226	$ 2,796	$ 1,792	$ 4,645
Post-modification outstanding recorded investment	$ 224	$ 3,239	$ 1,595	$ 5,099
Number of TDR loans with subsequent default \| Contract			1	4
Outstanding recorded investment on TDR loans with subsequent default			$ 175	$ 233
Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts \| Contract		2		2
Pre-modification outstanding recorded investment		$ 1,355		$ 1,355
Post-modification outstanding recorded investment		$ 1,341		$ 1,341
Commercial Loans [Member] \| Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts \| Contract		1		1
Pre-modification outstanding recorded investment		$ 1,165		$ 1,165
Post-modification outstanding recorded investment		$ 1,165		$ 1,165
Commercial Loans [Member] \| Business Banking [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts \| Contract		1		1
Pre-modification outstanding recorded investment		$ 190		$ 190
Post-modification outstanding recorded investment		$ 176		$ 176
Consumer Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts \| Contract	2	12	14	31
Pre-modification outstanding recorded investment	$ 74	$ 1,071	$ 1,109	$ 2,218
Post-modification outstanding recorded investment	$ 73	$ 1,128	$ 1,017	$ 2,236
Consumer Loans [Member] \| Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts \| Contract	2	12	14	31
Pre-modification outstanding recorded investment	$ 74	$ 1,071	$ 1,109	$ 2,218
Post-modification outstanding recorded investment	$ 73	$ 1,128	$ 1,017	$ 2,236
Number of TDR loans with subsequent default \| Contract			0	4
Outstanding recorded investment on TDR loans with subsequent default			$ 0	$ 233
Residential Real Estate Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Number of contracts \| Contract	2	6	6	15
Pre-modification outstanding recorded investment	$ 152	$ 370	$ 683	$ 1,072
Post-modification outstanding recorded investment	$ 151	$ 770	$ 578	$ 1,522
Number of TDR loans with subsequent default \| Contract			1	0
Outstanding recorded investment on TDR loans with subsequent default			$ 175	$ 0

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+ References

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Number of financing receivables that have been 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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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953682-111524

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Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

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