Short-Term Borrowings and Long-Term Debt Short Term (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Short-term Debt [Line Items]
Short-term Debt	$ 597,033,000	$ 674,077,000	$ 868,940,000
Collateralized Borrowings Availability At Discount Window	1,700,000,000	1,500,000,000
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Short-term Debt	253,470,000	267,844,000	378,068,000
Short-term Debt, Maximum Month-end Outstanding Amount	381,093,000	506,567,000	865,699,000
Repurchase Agreements [Member]
Short-term Debt [Line Items]
Short-term Debt	186,735,000	204,800,000	259,458,000
Short-term Debt, Maximum Month-end Outstanding Amount	235,780,000	279,414,000	274,546,000
Notes Payable, Other Payables [Member]
Short-term Debt [Line Items]
Short-term Debt	156,828,000	201,433,000	231,414,000
Short-term Debt, Maximum Month-end Outstanding Amount	196,562,000	243,637,000	347,401,000
Federal Reserve Bank Advances [Member]
Short-term Debt [Line Items]
Short-term Debt	0	0	0
Short-term Debt, Maximum Month-end Outstanding Amount	0	0	200,000,000
Other Debt Obligations [Member]
Short-term Debt [Line Items]
Short-term Debt	0	0	0
Short-term Debt, Maximum Month-end Outstanding Amount	$ 0	$ 0	$ 5,215,000