Loans - Loan Categories Narrative (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 payment	Dec. 31, 2012
Schedule of Loans by Loan Classification [Line Items]
Early Payment Default Period	4
Participation loans amount	$ 35.5	$ 28.6
Commercial real estate | Minimum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	15 years
Commercial real estate | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	25 years
Commercial and industrial | Minimum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	1 year
Commercial and industrial | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	7 years
Commercial construction | Minimum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	1 year
Commercial construction | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	3 years
Residential mortgages
Schedule of Loans by Loan Classification [Line Items]
Amount of loans serviced for others	21.5	22.2
Residential mortgages | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	30 years
Adjustable rate mortgage | Minimum
Schedule of Loans by Loan Classification [Line Items]
Loan-to-value ratio	80.00%
Fixed rate residential mortgage | Maximum
Schedule of Loans by Loan Classification [Line Items]
Loan-to-value ratio	97.00%
Home equity | Maximum
Schedule of Loans by Loan Classification [Line Items]
Loan-to-value ratio	80.00%
Home Equity Line of Credit
Schedule of Loans by Loan Classification [Line Items]
Term of interest only payments	10 years
Term of Principal and Interest Payments after Interest only term	15 years
Home Equity Loans | Minimum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	3 years
Period a loan has a fixed rate	3 years
Home Equity Loans | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	15 years
Period a loan has a fixed rate	15 years
Commercial loans
Schedule of Loans by Loan Classification [Line Items]
Participations loans sold that are still serviced amount	$ 53.9	$ 53.6