Income Taxes Components of Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred Tax Assets, Gross [Abstract]
Allowance for Loan Losses	$ 6,105	$ 5,957
Pension and Deferred Compensation Plans	4,140	3,965
Pension Liability Included in Accumulated Other Comprehensive Income	9,241	8,859
Other	608	669
Total Gross Deferred Tax Assets	20,094	19,450
Valuation Allowance for Deferred Tax Assets	0	0
Total Gross Deferred Tax Assets, Net of Valuation Allowance	20,094	19,450
Deferred Tax Liabilities, Gross [Abstract]
Pension Plans	8,178	8,758
Depreciation	1,475	1,347
Deferred Income	3,189	3,017
Net Unrealized Gains on Securities Available-for-Sale Included in Accumulated Other Comprehensive Income	3,690	4,465
Goodwill	5,225	5,036
Total Gross Deferred Tax Liabilites	$ 21,757	$ 22,623