Finance Receivables and Loans, Net (Schedule of Average Balance and Interest Income of Impaired Finance Receivables) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 701	$ 654	$ 1,316
Impaired Financing Receivable, Interest Income, Accrual Method	28	29	37
Consumer Portfolio Segment [Member] \| Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	600	575	1,190
Impaired Financing Receivable, Interest Income, Accrual Method	26	25	32
Consumer Portfolio Segment [Member] \| Automobile Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	344	295	317
Impaired Financing Receivable, Interest Income, Accrual Method	17	16	20
Consumer Portfolio Segment [Member] \| Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	256	280	873
Impaired Financing Receivable, Interest Income, Accrual Method	9	9	12
Consumer Portfolio Segment [Member] \| Mortgage Finance [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	8	8	12
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	0
Consumer Portfolio Segment [Member] \| Mortgage - Legacy [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	248	272	861
Impaired Financing Receivable, Interest Income, Accrual Method	9	9	12
Commercial Portfolio Segment [Member] \| Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	101	79	126
Impaired Financing Receivable, Interest Income, Accrual Method	2	4	5
Commercial Portfolio Segment [Member] \| Commercial And Industrial Automobile [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	35	33	61
Impaired Financing Receivable, Interest Income, Accrual Method	1	1	2
Commercial Portfolio Segment [Member] \| Commercial And Industrial Other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	60	41	59
Impaired Financing Receivable, Interest Income, Accrual Method	1	3	3
Commercial Portfolio Segment [Member] \| Commercial Real Estate Automobile [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	6	5	6
Impaired Financing Receivable, Interest Income, Accrual Method	$ 0	$ 0	$ 0

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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=66008989&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=66008989&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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