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, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	$ 969	$ 889	$ 756
Financing receivable, impaired, interest income	47	44	42
Consumer portfolio segment
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	730	707	633
Financing receivable, impaired, interest income	45	39	31
Consumer portfolio segment \| Automotive loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	510	478	391
Financing receivable, impaired, interest income	35	28	21
Consumer portfolio segment \| Real estate-backed loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	220	229	242
Financing receivable, impaired, interest income	10	11	10
Consumer portfolio segment \| Mortgage Finance operations
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	14	11	8
Financing receivable, impaired, interest income	1	1	0
Consumer portfolio segment \| Mortgage - Legacy
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	206	218	234
Financing receivable, impaired, interest income	9	10	10
Commercial portfolio segment
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	239	182	123
Financing receivable, impaired, interest income	2	5	11
Commercial portfolio segment \| Automotive loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	113	93	49
Financing receivable, impaired, interest income	2	4	2
Commercial portfolio segment \| Real estate-backed loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	5	5	5
Financing receivable, impaired, interest income	0	1	0
Commercial portfolio segment \| Other loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	121	84	69
Financing receivable, impaired, interest income	$ 0	$ 0	$ 9

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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5258-111524

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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.

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