Loans (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Nonaccrual loans
Total nonaccruing loans	$ 1,645	$ 1,828
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more	46	61
Total nonperforming loans	1,691	1,889
Nonaccrual loans held for sale [Member]
Nonaccrual loans
Total nonaccruing loans	65	91
Commercial loans [Member]
Nonaccrual loans
Total nonaccruing loans	654	825
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more	3	14
Commercial loans [Member] | Construction and land loans [Member]
Nonaccrual loans
Total nonaccruing loans	101	103
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more
Commercial loans [Member] | Other real estate [Member]
Nonaccrual loans
Total nonaccruing loans	374	512
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more		1
Commercial loans [Member] | Business banking and middle markets enterprises [Member]
Nonaccrual loans
Total nonaccruing loans	46	58
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more	2	11
Commercial loans [Member] | Global banking [Member]
Nonaccrual loans
Total nonaccruing loans	114	137
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more
Commercial loans [Member] | Other commercial [Member]
Nonaccrual loans
Total nonaccruing loans	19	15
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more	1	2
Consumer loans [Member]
Nonaccrual loans
Total nonaccruing loans	926	912
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more	43	47
Consumer loans [Member] | Residential mortgages, excluding home equity mortgages [Member]
Nonaccrual loans
Total nonaccruing loans	844	815
Consumer loans [Member] | Home equity mortgages [Member]
Nonaccrual loans
Total nonaccruing loans	77	89
Consumer loans [Member] | Total residential mortgages [Member]
Nonaccrual loans
Total nonaccruing loans	921	904
Consumer loans [Member] | Credit Card Receivable [Member]
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more	17	20
Consumer loans [Member] | Other consumer [Member]
Nonaccrual loans
Total nonaccruing loans	5	8
Accruing loans contractually past due 90 days or more:
Total accruing loans contractually past due 90 days or more	$ 26	$ 27