Finance Receivables And Loans, Net (Average Balance And Interest Income Of Impaired Finance Receivables) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Financing Receivable, Impaired [Line Items]
Average balance	$ 1,133	$ 1,122	$ 1,074	$ 1,191
Impaired Financing Receivable, Interest Income, Accrual Method	18	18	47	36
Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Average balance	97	56	91	23
Impaired Financing Receivable, Interest Income, Accrual Method	2	1	7	1
First Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Average balance	628	476	574	449
Impaired Financing Receivable, Interest Income, Accrual Method	10	5	21	13
Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Average balance	91	93	95	89
Impaired Financing Receivable, Interest Income, Accrual Method	1	1	3	3
Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Average balance	719	569	669	538
Impaired Financing Receivable, Interest Income, Accrual Method	11	6	24	16
Commercial And Industrial Automobile [Member]
Financing Receivable, Impaired [Line Items]
Average balance	229	306	212	321
Impaired Financing Receivable, Interest Income, Accrual Method	4	6	9	7
Commercial And Industrial Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Average balance	0	2	6	26
Impaired Financing Receivable, Interest Income, Accrual Method	0	1	0	6
Commercial And Industrial Other [Member]
Financing Receivable, Impaired [Line Items]
Average balance	37	54	32	95
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	5	1
Commercial Real Estate Automobile [Member]
Financing Receivable, Impaired [Line Items]
Average balance	51	104	57	141
Impaired Financing Receivable, Interest Income, Accrual Method	1	4	2	4
Commercial Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Average balance	0	31	7	47
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	0	1
Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Average balance	317	497	314	630
Impaired Financing Receivable, Interest Income, Accrual Method	$ 5	$ 11	$ 16	$ 19