Finance Receivables and Loans, Net (Troubled Debt Restructurings) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 1,300,000,000		$ 1,300,000,000		$ 1,300,000,000
Financing Receivable, Modifications, Number of Contracts	4,056	4,606	9,639	10,444
Financing Receivable, Modifications, Pre-Modification Recorded Investment	82,000,000	141,000,000	286,000,000	458,000,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	74,000,000	123,000,000	261,000,000	392,000,000
Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	3,961	4,414	9,320	9,699
Financing Receivable, Modifications, Pre-Modification Recorded Investment	67,000,000	68,000,000	151,000,000	147,000,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	59,000,000	57,000,000	130,000,000	125,000,000
Residential Mortgage [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	95	187	313	732
Financing Receivable, Modifications, Pre-Modification Recorded Investment	15,000,000	44,000,000	64,000,000	213,000,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	15,000,000	37,000,000	60,000,000	171,000,000
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	0	5	6	13
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	29,000,000	71,000,000	98,000,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	29,000,000	71,000,000	96,000,000
Commercial And Industrial Automobile [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	0	2	3	6
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	7,000,000	23,000,000	32,000,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	7,000,000	23,000,000	32,000,000
Commercial And Industrial Other [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	0	2	3	3
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	20,000,000	48,000,000	53,000,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	20,000,000	48,000,000	51,000,000
Commercial Real Estate Automobile [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	0	1	0	4
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	2,000,000	0	13,000,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 2,000,000	$ 0	$ 13,000,000