Finance Receivables And Loans, Net (Past Due Financing Receivables And Loans) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	$ 865	$ 1,227
60 - 89 days past due	189	286
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	307	323
Total past due	1,361	1,836
Current	98,262	98,491
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	99,623	100,327
Finance receivables and loans, net	99,624	100,328	99,123
Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	806	1,145
60 - 89 days past due	163	255
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	138	157
Total past due	1,107	1,557
Current	55,668	54,860
Finance receivables and loans, net	56,775	56,417
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	59	82
60 - 89 days past due	26	31
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	115	124
Total past due	200	237
Current	7,937	8,206
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	8,137	8,443
Finance receivables and loans, net	8,138	8,444
Commercial Loan [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	54	42
Total past due	54	42
Current	34,657	35,425
Finance receivables and loans, net	34,711	35,467
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	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	49	36
Total past due	49	36
Current	30,013	30,912
Finance receivables and loans, net	30,062	30,948
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	1,727	1,664
Finance receivables and loans, net	1,727	1,664
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	5	6
Total past due	5	6
Current	2,917	2,849
Finance receivables and loans, net	$ 2,922	$ 2,855