Finance Receivables And Loans, Net (Redefaults) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Impaired, Commitment to Lend	$ 13		$ 25
Financing Receivable, Number of loans redefaulted within 12 months of being modified	1,343	219
Financing Receivable, Redefaults, Carrying Value Before Allowance	18	6
Redefault Charge-off	8	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	1,333	208
Financing Receivable, Redefaults, Carrying Value Before Allowance	16	2
Redefault Charge-off	8	1
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified	10	9
Financing Receivable, Redefaults, Carrying Value Before Allowance	2	2
Redefault Charge-off	0	1
First Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified	8	5
Financing Receivable, Redefaults, Carrying Value Before Allowance	2	1
Redefault Charge-off	0	0
Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified	2	4
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	1
Redefault Charge-off	0	1
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified	0	2
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	2
Redefault Charge-off	0	0
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	0	2
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	2
Redefault Charge-off	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	0	0
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	0
Redefault Charge-off	$ 0	$ 0