Finance Receivables And Loans, Net (Redefaults) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Impaired, Commitment to Lend	$ 18		$ 18		$ 25
Financing Receivable, Number of loans redefaulted within 12 months of being modified	1,416	180	2,759	399
Financing Receivable, Redefaults, Carrying Value Before Allowance	18	6	36	12
Redefault Charge-off	9	2	17	4
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	1,414	161	2,747	369
Financing Receivable, Redefaults, Carrying Value Before Allowance	18	1	34	3
Redefault Charge-off	9	1	17	2
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified	2	16	12	25
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	2	2	4
Redefault Charge-off	0	1	0	2
First Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified	2	7	10	12
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	2	2	3
Redefault Charge-off	0	1	0	1
Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Number of loans redefaulted within 12 months of being modified	0	9	2	13
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	0	0	1
Redefault Charge-off	0	0	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	3	0	5
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	3	0	5
Redefault Charge-off	0	0	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	0	4
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	1	0	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	0	1	0	1
Financing Receivable, Redefaults, Carrying Value Before Allowance	0	2	0	2
Redefault Charge-off	$ 0	$ 0	$ 0	$ 0