Income Taxes Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Statutory Tax Rate	35.00%	35.00%	35.00%
Effect Of Tax-Exempt Income	(5.00%)	(5.30%)	(5.80%)
Effect Of Low Income Housing Investments	(4.40%)	(4.30%)	(3.30%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses	0.90%	0.00%	0.00%
Bank Owned Life Insurance	(0.80%)	(0.60%)	(0.60%)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance	(0.60%)	4.60%	0.20%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost	0.50%	0.10%	0.10%
State Income Taxes, Net Of Federal Benefit	0.60%	(4.00%)	0.00%
Other, Net	0.30%	0.40%	0.10%
Effective Income Tax Rate	26.50%	25.90%	25.70%