Finance Receivables And Loans, Net (Past Due Financing Receivables And Loans) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	$ 1,315	$ 1,416
60 - 89 days past due	273	327
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	273	288
Total past due	1,861	2,031
Current	103,311	97,916
Finance receivables and loans, net	105,173	99,948
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	105,172	99,947	$ 100,777
Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	1,226	1,340
60 - 89 days past due	251	293
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	156	164
Total past due	1,633	1,797
Current	59,153	54,773
Finance receivables and loans, net	60,786	56,570
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	89	76
60 - 89 days past due	22	25
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	96	124
Total past due	207	225
Current	9,004	7,248
Finance receivables and loans, net	9,212	7,474
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	9,211	7,473
Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	0	0
60 - 89 days past due	0	9
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	21	0
Total past due	21	9
Current	35,154	35,895
Finance receivables and loans, net	35,175	35,904
Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	0	0
60 - 89 days past due	0	9
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	20	0
Total past due	20	9
Current	29,712	30,862
Finance receivables and loans, net	29,732	30,871
Commercial And Industrial Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	0	0
60 - 89 days past due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	0
Total past due	0	0
Current	2,149	1,882
Finance receivables and loans, net	2,149	1,882
Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	0	0
60 - 89 days past due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	1	0
Total past due	1	0
Current	3,293	3,151
Finance receivables and loans, net	$ 3,294	$ 3,151