Purchased Loans (Purchased Impaired Loans Balances) (Details) (Purchased Impaired Loans [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 7,749	[1]	$ 6,667	[2]
Outstanding Balance	8,913	[1]	7,521	[2]
Total commercial lending [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,402	[1]	852	[2]
Outstanding Balance	1,937	[1]	988	[2]
Total consumer lending [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	6,347	[1]	5,815	[2]
Outstanding Balance	6,976	[1]	6,533	[2]
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	354	[1]	140	[2]
Outstanding Balance	603	[1]	245	[2]
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,048	[1]	712	[2]
Outstanding Balance	1,334	[1]	743	[2]
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	3,650	[1]	3,049	[2]
Outstanding Balance	3,833	[1]	3,128	[2]
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	2,697	[1]	2,766	[2]
Outstanding Balance	$ 3,143	[1]	$ 3,405	[2]

[1] Represents National City and RBC Bank (USA) acquisitions.

[2] Represents National City acquisition.