Income Taxes Deferred Tax Assetss And Liabilities (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Interest on Income Taxes Expense	$ 563,000	$ 25,000	$ 86,000
Deferred Tax Assets Other Than Temporary Impairment Losses Investment Securities	14,900,000
Deferred Tax Assets, Net [Abstract]
Allowance for credit losses	95,788,000	96,408,000
Other than tempoprary impairment of investments	15,490,000	17,482,000
Loss and credit carryforwards	12,405,000	8,232,000
Postretirement and defined benefit plans	11,527,000	5,588,000
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Other	10,415,000	13,075,000
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	9,568,000	9,553,000
Other	16,262,000	7,476,000
Total gross deferred tax assets	171,455,000	157,814,000
Deferred Tax Liabilities [Abstract]
Unrealized holding gains on securities available for sale	14,025,000	10,769,000
Mortgage servicing rights	11,776,000	10,745,000
Premises and equipment	7,561,000	5,048,000
Acquisitions premiums/discounts	6,919,000	7,557,000
Direct leasing	6,174,000	5,069,000
Other	5,885,000	7,358,000
Total gross deferred tax liabilities	52,340,000	46,546,000
Net deferred tax asset before valuation allowance	119,115,000	111,268,000
Valuation allowance	(17,321,000)	(8,232,000)
Net deferred tax asset	101,794,000	103,036,000
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	441,000,000	452,000,000
Deferred Tax Asset Cumulative Amount Of Temporary Difference	18,000,000
Deferred Tax Asset Cumulative Amount Of Temporary Difference Net Of Federal Effect	11,700,000
Deferred Tax Assets Valuation Allowances Not Realizable	13,700,000
Deferred Tax Assets Valuation Allowances Not Realizable Net Of Tax Effect	$ 8,900,000
Tax Credit Carryforward, Expiration Dates	2031