Finance Receivables And Loans, Net (Financing Receivable Credit Quality Indicators) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	$ 70,847	$ 63,459
Consumer Loans Auto Financing Receivable [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	70,543	63,231
Consumer Loans Auto Financing Receivable [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	304	228
First Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	7,070	6,891
First Mortgage [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	6,626	6,610
First Mortgage [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	444	281
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	2,717	3,102
Home Equity [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	2,681	3,044
Home Equity [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	36	58
Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	9,787	9,993
Residential Mortgage [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	9,307	9,654
Residential Mortgage [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	$ 480	$ 339