Commitments, Contingencies and Credit Risk (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Lease Commitments
Rent expense under operating leases	$ 2,500,000	$ 3,000,000	$ 2,900,000
Projected minimum rental payments under the terms of leases
2013	1,413,000
2014	771,000
2015	637,000
2016	112,000
2017	4,000
Total	2,937,000
Maximum
Credit Commitments and Contingencies
Term for guarantee	1 year
Commitments to extend credit
Credit Commitments and Contingencies
Financial instruments whose contract amounts represent credit risk:	483,373,000	501,249,000
Standby letters of credit
Credit Commitments and Contingencies
Financial instruments whose contract amounts represent credit risk:	$ 12,305,000	$ 13,549,000