Finance Receivables and Loans, Net (Finance receivables and loans redefaulted during the period) (Details) - Consumer portfolio segment $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)
Consumer loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, modifications, subsequent default, number of loans	2,209	2,326
Financing receivable, modifications, subsequent default, gross carrying value	$ 26	$ 28
Financing receivables, impaired, troubled debt restructuring, charge-off amount	$ 16	$ 18
Automobile loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, modifications, subsequent default, number of loans	2,209	2,326
Financing receivable, modifications, subsequent default, gross carrying value	$ 26	$ 28
Financing receivables, impaired, troubled debt restructuring, charge-off amount	$ 16	$ 18

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No definition available.

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

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- Definition

Reflects the amount of the write-down related to a troubled debt restructuring.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

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