Finance Receivables and Loans, Net (Schedule of Financing Receivables, Non Accrual Status) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Jan. 01, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	$ 1,522	$ 1,036
Financing Receivable, Nonaccrual, No Allowance	706
Financing Receivable, Nonaccrual, Interest Income	8
Consumer portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	1,361	821
Financing Receivable, Nonaccrual, No Allowance	650
Consumer portfolio segment \| Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	1,256	762
Financing Receivable, Nonaccrual, No Allowance	604
Consumer portfolio segment \| Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	102	57
Financing Receivable, Nonaccrual, No Allowance	46
Consumer portfolio segment \| Mortgage Finance operations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	67	17
Financing Receivable, Nonaccrual, No Allowance	18
Consumer portfolio segment \| Mortgage - Legacy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	35	40
Financing Receivable, Nonaccrual, No Allowance	28
Consumer portfolio segment \| Other loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	3	2
Financing Receivable, Nonaccrual, No Allowance	0
Commercial portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	161	215
Financing Receivable, Nonaccrual, No Allowance	56
Commercial portfolio segment \| Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	40	73
Financing Receivable, Nonaccrual, No Allowance	10
Commercial portfolio segment \| Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	5	4
Financing Receivable, Nonaccrual, No Allowance	5
Commercial portfolio segment \| Other loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	116	$ 138
Financing Receivable, Nonaccrual, No Allowance	$ 41

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Amount of interest income on financing receivable on nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919258-210447

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919258-210447

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
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-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5111-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
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-Paragraph 16
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