Loans (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011		Jun. 30, 2011
Commercial and Consumer Loans
Total commercial	$ 37,417		$ 33,649
Total consumer	18,647		18,218
Total loans	56,064	[1]	51,867	[1]	49,612
Construction and other real estate [Member]
Commercial and Consumer Loans
Total commercial	7,977		7,860
Business banking and middle markets enterprises [Member]
Commercial and Consumer Loans
Total commercial	11,256		10,225
Global banking [Member]
Commercial and Consumer Loans
Total commercial	15,042		12,658
Other commercial [Member]
Commercial and Consumer Loans
Total commercial	3,142		2,906
Home equity mortgages [Member]
Commercial and Consumer Loans
Total consumer	2,455		2,563
Other residential mortgages [Member]
Commercial and Consumer Loans
Total consumer	14,758		14,113
Credit cards [Member]
Commercial and Consumer Loans
Total consumer	783		828
Other consumer [Member]
Commercial and Consumer Loans
Total consumer	$ 651		$ 714

[1] The following table summarizes assets and liabilities related to variable interest entities ("VIEs") as of June 30, 2012 and December 31, 2011 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation.