Finance Receivables And Loans, Net Finance Receivables And Loans, Net (Redefaults) (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
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified [Line Item]	162	97	561	200
Financing Receivable, Redefaults, Carrying Value Before Allowance [Line Item]	$ 4	$ 2	$ 16	$ 7
Redefault Charge-off	1	1	5	2
Consumer Loans Auto Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified [Line Item]	145	88	514	176
Financing Receivable, Redefaults, Carrying Value Before Allowance [Line Item]	2	1	5	2
Redefault Charge-off	0	0	2	1
First Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified [Line Item]	5	0	17	5
Financing Receivable, Redefaults, Carrying Value Before Allowance [Line Item]	1	0	4	1
Redefault Charge-off	0	0	1	0
Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified [Line Item]	12	9	25	18
Financing Receivable, Redefaults, Carrying Value Before Allowance [Line Item]	1	1	2	1
Redefault Charge-off	1	1	2	1
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified [Line Item]	17	9	42	23
Financing Receivable, Redefaults, Carrying Value Before Allowance [Line Item]	2	1	6	2
Redefault Charge-off	1	1	3	1
Commercial And Industrial Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified [Line Item]	0	0	4	1
Financing Receivable, Redefaults, Carrying Value Before Allowance [Line Item]	0	0	3	3
Redefault Charge-off	0	0	0	0
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified [Line Item]	0	0	1	0
Financing Receivable, Redefaults, Carrying Value Before Allowance [Line Item]	0	0	2	0
Redefault Charge-off	0	0	0	0
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified [Line Item]	0	0	5	1
Financing Receivable, Redefaults, Carrying Value Before Allowance [Line Item]	0	0	5	3
Redefault Charge-off	$ 0	$ 0	$ 0	$ 0