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, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	$ 889	$ 756	$ 701
Financing receivable, impaired, interest income	44	42	28
Consumer portfolio segment \| Consumer loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	707	633	600
Financing receivable, impaired, interest income	39	31	26
Consumer portfolio segment \| Automobile loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	478	391	344
Financing receivable, impaired, interest income	28	21	17
Consumer portfolio segment \| Residential mortgage
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	229	242	256
Financing receivable, impaired, interest income	11	10	9
Consumer portfolio segment \| Mortgage Finance
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	11	8	8
Financing receivable, impaired, interest income	1	0	0
Consumer portfolio segment \| Mortgage - Legacy
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	218	234	248
Financing receivable, impaired, interest income	10	10	9
Commercial portfolio segment \| Commercial loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	182	123	101
Financing receivable, impaired, interest income	5	11	2
Commercial portfolio segment \| Commercial and industrial automotive
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	93	49	35
Financing receivable, impaired, interest income	4	2	1
Commercial portfolio segment \| Commercial and industrial other
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	84	69	60
Financing receivable, impaired, interest income	0	9	1
Commercial portfolio segment \| Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	5	5	6
Financing receivable, impaired, interest income	$ 1	$ 0	$ 0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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=84173941&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=84173941&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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