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, 2013	Dec. 31, 2012	Jun. 30, 2012
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	$ 96,993	$ 99,055	$ 119,913
Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	31,695	35,519
Commercial Loan [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	29,923	33,835
Commercial Loan [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	1,772	1,684
Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	27,518	30,270
Commercial And Industrial Automobile [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	26,118	28,978
Commercial And Industrial Automobile [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	1,400	1,292
Commercial And Industrial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	0	0
Commercial And Industrial Mortgage [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	0	0
Commercial And Industrial Mortgage [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	0	0
Commercial And Industrial Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	1,502	2,697
Commercial And Industrial Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	1,212	2,417
Commercial And Industrial Other [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	290	280
Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	2,675	2,552
Commercial Real Estate Automobile [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	2,593	2,440
Commercial Real Estate Automobile [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	82	112
Commercial Real Estate Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	0	0
Commercial Real Estate Mortgage [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	0	0
Commercial Real Estate Mortgage [Member] | Criticized Member
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	$ 0	$ 0