Troubled Debt Restructurings (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Loan	Dec. 31, 2013 Loan	Dec. 31, 2012 Loan
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans	51	63	198
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 37,781	$ 29,046	$ 90,747
Troubled Debt Restructurings, Post-Modification Recorded Balance	37,075	29,359	89,558
TDRs that Subsequently Defaulted, Number of Loans	5	5	14
TDRs that Subsequently Defaulted, Recorded Balance	4,453	849	8,304
Residential Real Estate
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans	0	9	11
Troubled Debt Restructurings, Pre-Modification Recorded Balance	0	1,907	2,280
Troubled Debt Restructurings, Post-Modification Recorded Balance	0	2,293	2,281
TDRs that Subsequently Defaulted, Number of Loans	0	1	0
TDRs that Subsequently Defaulted, Recorded Balance	0	265	0
Commercial Real Estate
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans	18	21	85
Troubled Debt Restructurings, Pre-Modification Recorded Balance	21,760	20,334	57,382
Troubled Debt Restructurings, Post-Modification Recorded Balance	21,803	20,334	56,120
TDRs that Subsequently Defaulted, Number of Loans	2	1	4
TDRs that Subsequently Defaulted, Recorded Balance	927	79	6,192
Other Commercial
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans	24	23	75
Troubled Debt Restructurings, Pre-Modification Recorded Balance	12,522	6,087	28,639
Troubled Debt Restructurings, Post-Modification Recorded Balance	11,884	6,087	28,711
TDRs that Subsequently Defaulted, Number of Loans	1	3	6
TDRs that Subsequently Defaulted, Recorded Balance	693	505	1,753
Home Equity
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans	6	2	10
Troubled Debt Restructurings, Pre-Modification Recorded Balance	3,385	147	1,358
Troubled Debt Restructurings, Post-Modification Recorded Balance	3,274	147	1,358
TDRs that Subsequently Defaulted, Number of Loans	2	0	3
TDRs that Subsequently Defaulted, Recorded Balance	2,833	0	301
Other Consumer
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans	3	8	17
Troubled Debt Restructurings, Pre-Modification Recorded Balance	114	571	1,088
Troubled Debt Restructurings, Post-Modification Recorded Balance	114	498	1,088
TDRs that Subsequently Defaulted, Number of Loans	0	0	1
TDRs that Subsequently Defaulted, Recorded Balance	$ 0	$ 0	$ 58