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Balance Sheet Offsetting - Financial Instruments Derivative Assets Liabilities and Resell Agreements Net of Amount Not Offset (Detail) - USD ($) $ in Thousands | Sep. 30, 2024 | Dec. 31, 2023
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Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Net Amount Recognized, Derivatives, Financial Assets | $ 96,708 | $ 119,723
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets | (27,674) | (32,431)
Gross Amount Not Offset Collateral, Derivatives, Financial Assets | (67,983) | (84,839)
Net Amount, Derivatives, Financial Assets | 1,051 | 2,453
Net Amount Recognized, Resell agreements, Financial Assets | 9,650 | 84,650
Gross Amounts Not Offset Financial Instruments, Resell Agreements | 0 | 0
Gross Amounts Not Offset Collateral, Resell Agreements, Financial Assets | (9,650) | (84,650)
Net Amount, Financial Assets, Resell Agreements | 0 | 0
Net Amount Recognized, Total Financial Assets | 106,358 | 204,373
Gross Amounts Not Offset Collateral, Financial Assets | (77,633) | (169,489)
Net Amount, Financial Assets | 1,051 | 2,453
Net Amount Recognized, Derivatives, Financial Liabilities | 44,056 | 41,311
Gross Amounts Not Offset Financial Instruments, Total Derivatives, Financial Liabilities | (27,674) | (32,431)
Gross Amounts Not Offset Collateral, Derivatives, Financial Liabilities | (16,382) | (8,580)
Net Amount, Derivatives, Financial Liabilities | 0 | 300
Net Amount Recognized, Repurchase Agreements, Financial Liabilities | 4,014,037 | 4,127,188
Gross Amounts Not Offset Financial Instruments, Repurchase Agreements, Financial Liabilities | 0 | 0
Gross Amounts Not Offset Collateral, Repurchase Agreements, Financial Liabilities | (4,014,037) | (4,127,188)
Net Amount, Repurchase Agreements, Financial Liabilities | 0 | 0
Net Amount Recognized, Total Financial Liabilities | 4,058,093 | 4,168,499
Gross Amounts Not Offset Collateral, Financial Liabilities | (4,030,419) | (4,135,768)
Net Amount, Financial Liabilities | 0 | 300
Counterparty H |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Net Amount Recognized, Derivatives, Financial Assets | 37,881 | 36,551
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets | (9,014) | (8,870)
Gross Amount Not Offset Collateral, Derivatives, Financial Assets | (28,867) | (27,170)
Net Amount, Derivatives, Financial Assets | 0 | 511
Net Amount Recognized, Derivatives, Financial Liabilities | 9,014 | 8,870
Gross Amounts Not Offset Financial Instruments, Total Derivatives, Financial Liabilities | (9,014) | (8,870)
Gross Amounts Not Offset Collateral, Derivatives, Financial Liabilities | 0 | 0
Net Amount, Derivatives, Financial Liabilities | 0 | 0
Counterparty F |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Net Amount Recognized, Derivatives, Financial Assets | 20,090 | 31,202
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets | (1,987) | (7,444)
Gross Amount Not Offset Collateral, Derivatives, Financial Assets | (17,170) | (22,954)
Net Amount, Derivatives, Financial Assets | 933 | 804
Net Amount Recognized, Derivatives, Financial Liabilities | 1,987 | 7,444
Gross Amounts Not Offset Financial Instruments, Total Derivatives, Financial Liabilities | (1,987) | (7,444)
Gross Amounts Not Offset Collateral, Derivatives, Financial Liabilities | 0 | 0
Net Amount, Derivatives, Financial Liabilities | 0 | 0
Counterparty B |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Net Amount Recognized, Derivatives, Financial Assets | 22,591 | 23,829
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets | (4,525) | (5,151)
Gross Amount Not Offset Collateral, Derivatives, Financial Assets | (18,066) | (18,472)
Net Amount, Derivatives, Financial Assets | 0 | 206
Net Amount Recognized, Derivatives, Financial Liabilities | 4,525 | 5,151
Gross Amounts Not Offset Financial Instruments, Total Derivatives, Financial Liabilities | (4,525) | (5,151)
Gross Amounts Not Offset Collateral, Derivatives, Financial Liabilities | 0 | 0
Net Amount, Derivatives, Financial Liabilities | 0 | 0
Counterparty E |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Net Amount Recognized, Derivatives, Financial Assets | 8,941 | 13,271
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets | (8,823) | (4,548)
Gross Amount Not Offset Collateral, Derivatives, Financial Assets | 0 | (8,723)
Net Amount, Derivatives, Financial Assets | 118 | 0
Net Amount Recognized, Derivatives, Financial Liabilities | 8,823 | 4,548
Gross Amounts Not Offset Financial Instruments, Total Derivatives, Financial Liabilities | (8,823) | (4,548)
Gross Amounts Not Offset Collateral, Derivatives, Financial Liabilities | 0 | 0
Net Amount, Derivatives, Financial Liabilities | 0 | 0
Other counterparties |  |
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Net Amount Recognized, Derivatives, Financial Assets | 7,205 | 14,870
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets | (3,325) | (6,418)
Gross Amount Not Offset Collateral, Derivatives, Financial Assets | (3,880) | (7,520)
Net Amount, Derivatives, Financial Assets | 0 | 932
Net Amount Recognized, Derivatives, Financial Liabilities | 19,707 | 15,298
Gross Amounts Not Offset Financial Instruments, Total Derivatives, Financial Liabilities | (3,325) | (6,418)
Gross Amounts Not Offset Collateral, Derivatives, Financial Liabilities | (16,382) | (8,580)
Net Amount, Derivatives, Financial Liabilities | $ 0 | $ 300

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