Finance Receivables And Loans, Net (Past Due Financing Receivables And Loans) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	$ 862	$ 1,001
60 - 89 days past due	190	256
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	334	337
Total past due	1,386	1,594
Current	97,737	97,461
Finance receivables and loans, net	99,123	99,055	118,986
Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	743	920
60 - 89 days past due	152	213
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	133	138
Total past due	1,028	1,271
Current	53,986	52,444
Finance receivables and loans, net	55,014	53,715
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	92	81
60 - 89 days past due	38	43
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	162	174
Total past due	292	298
Current	9,380	9,523
Finance receivables and loans, net	9,672	9,821
First Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	76	66
60 - 89 days past due	32	37
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	147	156
Total past due	255	259
Current	6,840	6,914
Finance receivables and loans, net	7,095	7,173
Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	16	15
60 - 89 days past due	6	6
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	15	18
Total past due	37	39
Current	2,540	2,609
Finance receivables and loans, net	2,577	2,648
Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	27	0
60 - 89 days past due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	39	25
Total past due	66	25
Current	34,371	35,494
Finance receivables and loans, net	34,437	35,519
Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	26	0
60 - 89 days past due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	24	16
Total past due	50	16
Current	29,205	30,254
Finance receivables and loans, net	29,255	30,270
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	0	0
Finance receivables and loans, net	0	0
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	1
Total past due	0	1
Current	2,562	2,696
Finance receivables and loans, net	2,562	2,697
Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 days past due	1	0
60 - 89 days past due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	15	8
Total past due	16	8
Current	2,604	2,544
Finance receivables and loans, net	2,620	2,552
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	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	0
Total past due	0	0
Current	0	0
Finance receivables and loans, net	$ 0	$ 0