Loans, Allowance for Credit Losses, and Credit Quality Troubled Debt Restructurings Subsequent Default (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	41	21
Recorded Investment	$ 2,391	$ 2,320
Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	1	0
Recorded Investment	297	0
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0	1
Recorded Investment	0	161
Home Equity Port Folio Segments [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	24	7
Recorded Investment	855	388
Installment and Credit Cards [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0	1
Recorded Investment	0	10
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	16	12
Recorded Investment	$ 1,239	$ 1,761