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Derivative Instruments - Summary of Notional Amounts of AFS's Trading Derivative Products (Detail) - AFS [Member] - Successor [Member] - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017
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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 | $ 375,951 | $ 379,497
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 | 1,463,331 | 1,428,264
Futures Contracts [Member] |  |
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items] |  |
Derivative products, Notional Amount | $ 1,805,000 | $ 1,655,000

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- Definition Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items] + References No definition available. + Details
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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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