Loans (Details 13) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Status of Commercial Loan Portfolio
Nonaccrual Loans	$ 1,645	$ 1,828
Accruing Loans Contractually Past Due 90 days or More	46	61
Total	37,417	33,649
Construction and other real estate [Member]
Status of Commercial Loan Portfolio
Total	7,977	7,860
Business banking and middle markets enterprises [Member]
Status of Commercial Loan Portfolio
Total	11,256	10,225
Global banking [Member]
Status of Commercial Loan Portfolio
Total	15,042	12,658
Other commercial [Member]
Status of Commercial Loan Portfolio
Total	3,142	2,906
Commercial Loan [Member]
Status of Commercial Loan Portfolio
Performing Loans	36,760	32,810
Nonaccrual Loans	654	825
Accruing Loans Contractually Past Due 90 days or More	3	14
Total	37,417	33,649
Commercial Loan [Member] | Construction and other real estate [Member]
Status of Commercial Loan Portfolio
Performing Loans	7,502	7,244
Nonaccrual Loans	475	615
Accruing Loans Contractually Past Due 90 days or More		1
Total	7,977	7,860
Commercial Loan [Member] | Business banking and middle markets enterprises [Member]
Status of Commercial Loan Portfolio
Performing Loans	11,208	10,156
Nonaccrual Loans	46	58
Accruing Loans Contractually Past Due 90 days or More	2	11
Total	11,256	10,225
Commercial Loan [Member] | Global banking [Member]
Status of Commercial Loan Portfolio
Performing Loans	14,928	12,521
Nonaccrual Loans	114	137
Accruing Loans Contractually Past Due 90 days or More
Total	15,042	12,658
Commercial Loan [Member] | Other commercial [Member]
Status of Commercial Loan Portfolio
Performing Loans	3,122	2,889
Nonaccrual Loans	19	15
Accruing Loans Contractually Past Due 90 days or More	1	2
Total	$ 3,142	$ 2,906