Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Sechedule of Effective Income Tax Rate Reconciliation [Abstract]
Statutory rate	35.00%	35.00%	35.00%
Increase (decrease) in rate due to:
Effective Income Tax Rate Reconciliation, Tax Exempt Income	(3.23%)	(3.04%)	(3.36%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Life Insurance	(3.10%)	(3.26%)	(3.94%)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes	0.94%	0.72%	0.68%
Effective Income Tax Rate Reconciliation, Tax Credits	(2.15%)	(2.12%)	(2.37%)
Effective Income Tax Rate Reconciliation, Deductions, Dividends	(0.21%)	(0.24%)	(0.29%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Meals and Entertainment	0.25%	0.29%	0.30%
Effective Income Tax Rate Reconciliation, Other Adjustments	0.83%	0.48%	0.47%
Effective tax rates	28.33%	27.83%	26.49%