Finance Receivables And Loans, Net (Past Due Financing Receivables And Loans) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	$ 950	$ 916
60 - 89 days past due	249	212
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	442	532
Total past due	1,641	1,660
Current	119,618	112,260
Loans and Leases Receivable Excluding Fair Value Option Election	121,259	113,920
Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	848	802
60 - 89 days past due	197	162
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	191	179
Total past due	1,236	1,143
Current	69,611	62,316
Loans and Leases Receivable Excluding Fair Value Option Election	70,847	63,459
First Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	76	91
60 - 89 days past due	38	35
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	161	162
Total past due	275	288
Current	6,795	6,603
Loans and Leases Receivable Excluding Fair Value Option Election	7,070	6,891
Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	17	21
60 - 89 days past due	12	11
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	13	18
Total past due	42	50
Current	2,675	3,052
Loans and Leases Receivable Excluding Fair Value Option Election	2,717	3,102
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	93	112
60 - 89 days past due	50	46
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	174	180
Total past due	317	338
Current	9,470	9,655
Loans and Leases Receivable Excluding Fair Value Option Election	9,787	9,993
Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	7	0
60 - 89 days past due	2	1
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	58	126
Total past due	67	127
Current	34,735	34,690
Loans and Leases Receivable Excluding Fair Value Option Election	34,802	34,817
Commercial And Industrial Mortgage [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	686	1,911
Loans and Leases Receivable Excluding Fair Value Option Election	686	1,911
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	1	1
Total past due	1	1
Current	2,557	1,240
Loans and Leases Receivable Excluding Fair Value Option Election	2,558	1,241
Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	2	2
60 - 89 days past due	0	1
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	18	34
Total past due	20	37
Current	2,559	2,448
Loans and Leases Receivable Excluding Fair Value Option Election	2,579	2,485
Commercial Real Estate Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	0	0
60 - 89 days past due	0	2
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	12
Total past due	0	14
Current	0	0
Loans and Leases Receivable Excluding Fair Value Option Election	0	14
Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	9	2
60 - 89 days past due	2	4
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	77	173
Total past due	88	179
Current	40,537	40,289
Loans and Leases Receivable Excluding Fair Value Option Election	$ 40,625	$ 40,468