Securitizations And Variable Interest Entities (Schedule Of Variable Interest Entities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Variable Interest Entity [Line Items]
Assets of nonconsolidated variable interest entities	$ 776	$ 899
Maximum exposure to loss in nonconsolidated VIEs	1,078	939
Total consoldiated involvement with VIEs	40,662	40,123
Consumer Loans Auto Financing Receivable [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	21,424	19,072
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	0	0
Assets of nonconsolidated variable interest entities	776	899
Maximum exposure to loss in nonconsolidated VIEs	776	899
Commercial Automobile [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	18,563	20,511
Commercial Other [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	563	564
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	112	(24)
Assets of nonconsolidated variable interest entities	0	0
Maximum exposure to loss in nonconsolidated VIEs	$ 302	$ 40