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Investments - Gross Unrealized Gains and Losses and Cost of Equity (Detail) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022
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Schedule Of Trading Securities And Other Trading Assets [Line Items] |  |
Equity securities, Cost | $ 44,046 | $ 50,185
Equity securities, Gross Unrealized Gains | 13,101 | 11,873
Equity securities | $ 57,147 | $ 62,058

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