Loans, Allowance for Loan and Lease Losses, and Reserve for Off-Balance Sheet Credit Commitments (Details 7) (USD $)	3 Months Ended			3 Months Ended			3 Months Ended
	Mar. 31, 2013 item	Mar. 31, 2012 Total Troubled Debt Restructured Loans That Subsequently Defaulted item	Mar. 31, 2013 Total Troubled Debt Restructured Loans That Subsequently Defaulted item	Mar. 31, 2012 Commercial item	Mar. 31, 2013 Commercial item	Mar. 31, 2013 Home equity loans and lines of credit item	Mar. 31, 2012 Land item
Troubled debt restructured loans
Number of contracts		3	3	1	2	1	2
Period-End Outstanding Principal		$ 6,365,000	$ 2,031,000	$ 26,000	$ 1,886,000	$ 145,000	$ 6,339,000
Period-End Specific Reserve		3,328,000		10,000			3,318,000
Decrease in TDR loans	14,400,000
Number of notes into which an original note is separated	2
Commitments to lend additional funds on restructured loans	$ 1,200,000