Loans, Allowance for Credit Losses, and Credit Quality Loans Modified in a Troubled Debt Restructuring (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015 loan	Mar. 31, 2014 loan
Financing Receivable, Modifications [Line Items]
Number of Loans	77	68
Recorded Investment	$ 11,409	$ 14,082
Unpaid Principal Balance	11,598	18,833
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	2	8
Recorded Investment	196	3,446
Unpaid Principal Balance	208	7,218
Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	5	4
Recorded Investment	3,585	5,298
Unpaid Principal Balance	3,641	5,781
Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	4	4
Recorded Investment	3,030	1,643
Unpaid Principal Balance	3,042	1,676
Home Equity Port Folio Segments [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	36	30
Recorded Investment	1,782	935
Unpaid Principal Balance	1,843	1,218
Installment and Credit Cards [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0	1
Recorded Investment	0	10
Unpaid Principal Balance	0	20
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	30	21
Recorded Investment	2,816	2,750
Unpaid Principal Balance	$ 2,864	$ 2,920

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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=28368275&loc=SL6953676-111524

+ Details

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- Definition

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

+ References

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- Definition

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

+ References

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