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Securitizations and Variable Interest Entities (Schedule of Quantitative Information and Net Credit Losses about Securitized and Other Financial Assets Managed Together) (Details) - Consumer Automotive Industry Sector - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
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Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019 | Dec. 31, 2019
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together [Line Items] |  |  |  |  |
Loans managed and securitized, principal amount outstanding | $ 379 |  | $ 379 |  | $ 624
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Delinquent Amount at End of Period | 6 |  | 6 |  | 8
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Net Credit Losses During Period | 0 | $ 3 | 1 | $ 5 |
Whole Loan Sales |  |  |  |  |
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together [Line Items] |  |  |  |  |
Loans managed and securitized, principal amount outstanding | 103 |  | 103 |  | 207
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Delinquent Amount at End of Period | 1 |  | 1 |  | 2
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Net Credit Losses During Period | 0 | 1 | 0 | 1 |
Off-balance sheet variable interest entities |  |  |  |  |
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together [Line Items] |  |  |  |  |
Loans managed and securitized, principal amount outstanding | 276 |  | 276 |  | 417
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Delinquent Amount at End of Period | 5 |  | 5 |  | $ 6
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Net Credit Losses During Period | $ 0 | $ 2 | $ 1 | $ 4 |

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- Definition This is the amount of the financial instruments that are considered delinquent (past due) at the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (e)(4) -URI http://asc.fasb.org/extlink&oid=118948506&loc=d3e107314-111719 + Details
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- Definition 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. + References No definition available. + Details
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- Definition Net credit losses are charge-offs and are based on total loans outstanding during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (e)(5) -URI http://asc.fasb.org/extlink&oid=118948506&loc=d3e107314-111719 + Details
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- Definition This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118948506&loc=d3e107314-111719 + Details
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