Loans (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012
Receivables were Modified and Became Classified as TDR Loans
Total	$ 52	$ 200
Commercial loans [Member]
Receivables were Modified and Became Classified as TDR Loans
Total		92
Commercial loans [Member] | Construction and other real estate [Member]
Receivables were Modified and Became Classified as TDR Loans
Total		70
Commercial loans [Member] | Business banking and middle markets enterprises [Member]
Receivables were Modified and Became Classified as TDR Loans
Total		22
Commercial loans [Member] | Global banking [Member]
Receivables were Modified and Became Classified as TDR Loans
Total
Commercial loans [Member] | Other commercial [Member]
Receivables were Modified and Became Classified as TDR Loans
Total
Consumer loans [Member]
Receivables were Modified and Became Classified as TDR Loans
Total	52	108
Consumer loans [Member] | Residential mortgages [Member]
Receivables were Modified and Became Classified as TDR Loans
Total	52	108
Consumer loans [Member] | Credit cards [Member]
Receivables were Modified and Became Classified as TDR Loans
Total