Finance Receivables And Loans, Net (Schedule Of Pass And Criticized Credit Quality Indicators Of Finance Receivables) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	$ 34,802	$ 34,817
Commercial And Industrial Automobile [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	32,766	32,464
Commercial And Industrial Automobile [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,036	2,353
Commercial And Industrial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	686	1,911
Commercial And Industrial Mortgage [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	667	1,760
Commercial And Industrial Mortgage [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	19	151
Commercial And Industrial Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,558	1,241
Commercial And Industrial Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,306	883
Commercial And Industrial Other [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	252	358
Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,579	2,485
Commercial Real Estate Automobile [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,471	2,305
Commercial Real Estate Automobile [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	108	180
Commercial Real Estate Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	0	14
Commercial Real Estate Mortgage [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	0	0
Commercial Real Estate Mortgage [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	0	14
Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	40,625	40,468
Commercial Loan [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	38,210	37,412
Commercial Loan [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	$ 2,415	$ 3,056