Asset Quality (Narrative) (Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Troubled debt restructurings (TDRs)	$ 2,842,000,000		$ 2,859,000,000
Specific reserves in ALLL for the TDR portfolio	500,000,000		600,000,000
Nonperforming loans	3,321,000,000		3,254,000,000
Exclusions from TDRs	1,700,000,000	1,600,000,000
Equipment Lease Financing [Member]
Nonperforming loans	7,000,000		13,000,000
Equipment Lease Financing [Member] | Exclusion From Impaired Loans Pursuant To Authoritative Lease Accounting Guidance [Member]
Nonperforming loans	7,000,000		12,000,000
Nonperforming Status [Member]
Troubled debt restructurings (TDRs)	1,531,000,000		1,589,000,000
Accruing [Member]
Troubled debt restructurings (TDRs)	$ 1,103,000,000		$ 1,037,000,000