Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Future minimum rental payments [Abstract]
2013	$ 1,177,000
2014	1,006,000
2015	957,000
2016	828,000
2017	828,000
Thereafter	2,287,000
Total	7,083,000
Rent expense applicable to operating leases	1,500,000	1,500,000	1,200,000
Commitments to extend credit [Abstract]
Guarantee expiration period	1 year
Collateral supporting commitments (in hundredths)	100.00%
Loss on commitments	0	0	0
Commitments [Abstract]
Loan commitments, fixed rate	17,304,000
Loan commitment, variable rate	163,210,000
Stand by letters of credit	1,114,000
Total commitments	$ 181,628,000