Finance Receivables And Loans, Net (Average Balance And Interest Income Of Impaired Finance Receivables) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 654	$ 1,316	$ 1,439
Impaired Financing Receivable, Interest Income, Accrual Method	29	37	56
Consumer Portfolio Segment [Member] \| Automobile Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	295	317	278
Impaired Financing Receivable, Interest Income, Accrual Method	16	20	18
Consumer Portfolio Segment [Member] \| Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	280	873	908
Impaired Financing Receivable, Interest Income, Accrual Method	9	12	29
Commercial Portfolio Segment [Member] \| Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	79	126	253
Impaired Financing Receivable, Interest Income, Accrual Method	4	5	9
Commercial Portfolio Segment [Member] \| Commercial And Industrial Automobile [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	33	61	152
Impaired Financing Receivable, Interest Income, Accrual Method	1	2	6
Commercial Portfolio Segment [Member] \| Commercial And Industrial Other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	41	59	72
Impaired Financing Receivable, Interest Income, Accrual Method	3	3	2
Commercial Portfolio Segment [Member] \| Commercial Real Estate Automobile [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	5	6	29
Impaired Financing Receivable, Interest Income, Accrual Method	$ 0	$ 0	$ 1

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- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5258-111524

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- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

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