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v3.23.3

Investments - Additional Information (Detail) $ in Thousands | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2023 USD ($) Security | Sep. 30, 2022 USD ($) | Sep. 30, 2023 USD ($) Security | Sep. 30, 2022 USD ($) | Jun. 30, 2023 USD ($) | Dec. 31, 2022 USD ($)
Marketable Securities [Line Items] |  |  |  |  |  |
Individual fixed maturity held in unrealized loss position | Security | 202 |  | 202 |  |  |
Number of fixed maturity securities, allowance for credit loss | Security | 471 |  | 471 |  |  |
Fixed maturity securities, held-to-maturity, allowance for credit losses | $ 188 |  | $ 188 |  | $ 204 | $ 239
Available-for-sale, Allowance for Credit Losses | 0 |  | 0 |  |  | 0
Net realized gains on investments | 5,133 | $ 585 | 5,466 | $ 2,402 |  |
Net unrealized gains (losses) on equity securities | (7,309) | $ (4,082) | (3,892) | $ (12,984) |  |
Corporate Bonds [Member] |  |  |  |  |  |
Marketable Securities [Line Items] |  |  |  |  |  |
Fixed maturity securities, held-to-maturity, allowance for credit losses | $ 150 |  | $ 150 |  | 161 | 196
Number of majority securities | Security | 18 |  | 18 |  |  |
States and Political Subdivisions [Member] |  |  |  |  |  |
Marketable Securities [Line Items] |  |  |  |  |  |
Fixed maturity securities, held-to-maturity, allowance for credit losses | $ 37 |  | $ 37 |  | $ 41 | $ 40
Number of majority securities | Security | 450 |  | 450 |  |  |
Corporate Fixed Income Securities [Member] | Maximum [Member] |  |  |  |  |  |
Marketable Securities [Line Items] |  |  |  |  |  |
Investments maturity period using default rate |  |  | 20 years |  |  |

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