Income Taxes (Details 3)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Effective Income Tax Rate Reconciliation
Federal income tax rate at statutory rate	35.00%	35.00%	35.00%
Increases (decreases) resulting from:
Tax-exempt interest and dividends	(4.90%)	(7.00%)	34.10%
State income taxes (net of federal income taxes)	3.50%	3.80%	4.20%
Bank owned life insurance	(1.90%)	(2.80%)	13.30%
Valuation allowance	0.00%	(3.30%)	(0.50%)
Federal tax credits	(0.30%)	(0.90%)	3.90%
Tax reserve adjustments	(1.80%)	(0.60%)	10.80%
Compensation deduction limitations	0.30%	0.70%	(4.80%)
Other	(0.20%)	(1.10%)	1.90%
Effective income tax rate	29.70%	23.80%	97.90%