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Derivative Instruments - Summary of Notional Amounts of AFS's Trading Derivative Products (Details) - USD ($) $ in Millions | Sep. 30, 2024 | Dec. 31, 2023
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AFS [Member] | Interest Rate Swap [Member] |  |
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items] |  |
Derivative products, Notional Amount | $ 153 | $ 167
AFS [Member] | Interest Rate Swaps-Pay-Fixed/Receive-Variable [Member] |  |
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items] |  |
Derivative products, Notional Amount | 137 | 141
Variable Interest Entity, Primary Beneficiary [Member] | Interest Rate Swap [Member] |  |
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items] |  |
Derivative products, Notional Amount | 1,743 | 1,662
Variable Interest Entity, Primary Beneficiary [Member] | Interest Rate Swaps-Pay-Fixed/Receive-Variable [Member] |  |
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items] |  |
Derivative products, Notional Amount | $ 847 | $ 864

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- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A + Details
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