Finance Receivables And Loans, Net (Average Balance And Interest Income Of Impaired Finance Receivables) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 1,316	$ 1,439	$ 1,109
Impaired Financing Receivable, Interest Income, Accrual Method	37	56	55
Consumer Loans Auto Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	317	278	131
Impaired Financing Receivable, Interest Income, Accrual Method	20	18	12
Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	873	908	693
Impaired Financing Receivable, Interest Income, Accrual Method	12	29	28
Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	126	253	285
Impaired Financing Receivable, Interest Income, Accrual Method	5	9	15
Commercial And Industrial Automobile [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	61	152	178
Impaired Financing Receivable, Interest Income, Accrual Method	2	6	8
Commercial And Industrial Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	0	0	5
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	0
Commercial And Industrial Other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	59	72	32
Impaired Financing Receivable, Interest Income, Accrual Method	3	2	6
Commercial Real Estate Automobile [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	6	29	64
Impaired Financing Receivable, Interest Income, Accrual Method	0	1	1
Commercial Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	0	0	6
Impaired Financing Receivable, Interest Income, Accrual Method	$ 0	$ 0	$ 0