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Allowance for Loan Losses and Credit Quality of Loans, Troubled Debt Restructurings (Details) $ in Thousands | 3 Months Ended
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Mar. 31, 2017 USD ($) Contract | Mar. 31, 2016 USD ($) Contract
Financing Receivable, Modifications [Line Items] |  |
Number of contracts | Contract | 3 | 16
Pre-modification outstanding recorded investment | $ 219 | $ 1,566
Post-modification outstanding recorded investment | $ 215 | $ 1,389
Number of TDR loans with subsequent default | Contract | 0 | 1
Outstanding recorded investment on TDR loans with subsequent default | $ 0 | $ 175
Consumer Loans [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of contracts | Contract | 2 | 12
Pre-modification outstanding recorded investment | $ 78 | $ 1,035
Post-modification outstanding recorded investment | $ 77 | $ 952
Consumer Loans [Member] | Home Equity [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of contracts | Contract | 2 | 12
Pre-modification outstanding recorded investment | $ 78 | $ 1,035
Post-modification outstanding recorded investment | $ 77 | $ 952
Residential Real Estate Mortgages [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of contracts | Contract | 1 | 4
Pre-modification outstanding recorded investment | $ 141 | $ 531
Post-modification outstanding recorded investment | $ 138 | $ 437
Number of TDR loans with subsequent default | Contract | 0 | 1
Outstanding recorded investment on TDR loans with subsequent default | $ 0 | $ 175

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- Definition 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=66008989&loc=SL6953676-111524 + 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=66008989&loc=SL6953676-111524 + Details
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