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Fair Values of Assets and Liabilities - Quantitative Inputs and Assumptions Used in Level 3 Fair Value Measurements (Detail) - USD ($) $ in Thousands | Sep. 30, 2024 | Dec. 31, 2023
--- | --- | ---
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Other Investments | $ 24,592 | $ 50,871
Assets | 1,259,749 | 1,161,482
Limited Partnership Investment [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Assets | 29,757 | 27,137
Level 3 [Member] |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Other Investments | 5,732 | 6,182
Assets | $ 35,489 | $ 33,319

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