Short Term Borrowings (Details 1) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Short Term Borrowings (Additional Textual) [Abstract]
Funding availability of commercial paper program	$ 500,000,000
Deposits with the Federal Reserve	2,800,000,000
Outstanding borrowings under commercial paper program	0	0
Federal Reserve Bank of Cleveland [Member]
Short-term Borrowings (Textual) [Abstract]
Unused secured borrowing capacity	12,300,000,000
Federal Home Loan Bank [Member]
Short-term Borrowings (Textual) [Abstract]
Unused secured borrowing capacity	$ 6,400,000,000