Allowance for Credit Losses (Schedule of Consumer Credit Exposure, Credit Risk Profile Based on Payment Activity) (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Direct Retail Lending [Member]
Retail credit exposure, amount	$ 13,679	$ 13,749
Direct Retail Lending [Member] | Performing Financing Receivable [Member]
Retail credit exposure, amount	13,507	13,558
Direct Retail Lending [Member] | Nonperforming Financing Receivable [Member]
Retail credit exposure, amount	172	191
Retail Revolving Credit [Member]
Retail credit exposure, amount	2,091	2,127
Retail Revolving Credit [Member] | Performing Financing Receivable [Member]
Retail credit exposure, amount	2,091	2,127
Retail Residential Mortgage [Member]
Retail credit exposure, amount	18,372	17,550
Retail Residential Mortgage [Member] | Performing Financing Receivable [Member]
Retail credit exposure, amount	18,080	17,084
Retail Residential Mortgage [Member] | Nonperforming Financing Receivable [Member]
Retail credit exposure, amount	292	466
Retail Sales Finance [Member]
Retail credit exposure, amount	7,236	7,050
Retail Sales Finance [Member] | Performing Financing Receivable [Member]
Retail credit exposure, amount	7,229	7,044
Retail Sales Finance [Member] | Nonperforming Financing Receivable [Member]
Retail credit exposure, amount	7	6
Retail Specialized Lending [Member]
Retail credit exposure, amount	4,842	4,550
Retail Specialized Lending [Member] | Performing Financing Receivable [Member]
Retail credit exposure, amount	4,801	4,501
Retail Specialized Lending [Member] | Nonperforming Financing Receivable [Member]
Retail credit exposure, amount	$ 41	$ 49