Finance Receivables And Loans, Net (Impaired Financing Receivables) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	$ 1,478	$ 1,434
Carrying value before allowance	1,473	1,349
Impaired Financing Receivable, Related Allowance	259	228
Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	270	260
Carrying value before allowance	270	260
Impaired Financing Receivable, Related Allowance	22	16
Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	938	958
Carrying value before allowance	933	873
Impaired Financing Receivable, Related Allowance	209	186
First Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	790	811
Carrying value before allowance	784	725
Impaired Financing Receivable, Related Allowance	149	137
Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	148	147
Carrying value before allowance	149	148
Impaired Financing Receivable, Related Allowance	60	49
Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	270	216
Carrying value before allowance	270	216
Impaired Financing Receivable, Related Allowance	28	26
Commercial And Industrial Automobile [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	168	146
Carrying value before allowance	168	146
Impaired Financing Receivable, Related Allowance	10	7
Commercial And Industrial Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	0	0
Carrying value before allowance	0	0
Impaired Financing Receivable, Related Allowance	0	0
Commercial And Industrial Other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	63	33
Carrying value before allowance	63	33
Impaired Financing Receivable, Related Allowance	7	7
Commercial Real Estate Automobile [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	39	37
Carrying value before allowance	39	37
Impaired Financing Receivable, Related Allowance	11	12
Commercial Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	0	0
Carrying value before allowance	0	0
Impaired Financing Receivable, Related Allowance	0	0
Impaired With No Allowance Member
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	203	286
Impaired With No Allowance Member | Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	0	90
Impaired With No Allowance Member | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	127	124
Impaired With No Allowance Member | First Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	125	123
Impaired With No Allowance Member | Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	2	1
Impaired With No Allowance Member | Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	76	72
Impaired With No Allowance Member | Commercial And Industrial Automobile [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	54	54
Impaired With No Allowance Member | Commercial And Industrial Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	0	0
Impaired With No Allowance Member | Commercial And Industrial Other [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	10	9
Impaired With No Allowance Member | Commercial Real Estate Automobile [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	12	9
Impaired With No Allowance Member | Commercial Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	0	0
Impaired With Allowance Member
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	1,270	1,063
Impaired With Allowance Member | Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	270	170
Impaired With Allowance Member | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	806	749
Impaired With Allowance Member | First Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	659	602
Impaired With Allowance Member | Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	147	147
Impaired With Allowance Member | Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	194	144
Impaired With Allowance Member | Commercial And Industrial Automobile [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	114	92
Impaired With Allowance Member | Commercial And Industrial Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	0	0
Impaired With Allowance Member | Commercial And Industrial Other [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	53	24
Impaired With Allowance Member | Commercial Real Estate Automobile [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	27	28
Impaired With Allowance Member | Commercial Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Carrying value before allowance	$ 0	$ 0