Finance Receivables And Loans, Net (Schedule Of Pass And Criticized Credit Quality Indicators Of Finance Receivables) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	$ 35,847	$ 34,817
Commercial And Industrial Automobile [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	33,739	32,464
Commercial And Industrial Automobile [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,108	2,353
Commercial And Industrial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	1,146	1,911
Commercial And Industrial Mortgage [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	1,094	1,760
Commercial And Industrial Mortgage [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	52	151
Commercial And Industrial Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,435	1,241
Commercial And Industrial Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,123	883
Commercial And Industrial Other [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	312	358
Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,526	2,485
Commercial Real Estate Automobile [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	2,352	2,305
Commercial Real Estate Automobile [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	174	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	41,954	40,468
Commercial Loan [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	39,308	37,412
Commercial Loan [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Commercial	$ 2,646	$ 3,056