Finance Receivables and Loans, Net (Finance Receivables and Loans Redefaulted During the Period) (Details) - Consumer $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021 USD ($) loan	Jun. 30, 2020 USD ($) loan	Jun. 30, 2021 USD ($) loan	Jun. 30, 2020 USD ($) loan
Accounts, Notes, Loans and Financing Receivable
Number of loans \| loan	1,754	1,119	4,570	2,283
Amortized cost	$ 22	$ 11	$ 55	$ 24
Charge-off amount	$ 11	$ 8	$ 31	$ 17
Automotive loan
Accounts, Notes, Loans and Financing Receivable
Number of loans \| loan	1,751	1,119	4,565	2,283
Amortized cost	$ 22	$ 11	$ 55	$ 24
Charge-off amount	$ 11	$ 8	$ 31	$ 17
Mortgage Finance
Accounts, Notes, Loans and Financing Receivable
Number of loans \| loan	1	0	1	0
Amortized cost	$ 0	$ 0	$ 0	$ 0
Charge-off amount	$ 0	$ 0	$ 0	$ 0
Mortgage - Legacy
Accounts, Notes, Loans and Financing Receivable
Number of loans \| loan	2	0	4	0
Amortized cost	$ 0	$ 0	$ 0	$ 0
Charge-off amount	$ 0	$ 0	$ 0	$ 0

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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953682-111524

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Amount of financing receivable modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953682-111524

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

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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=121585226&loc=d3e18845-111554

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