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v3.23.1

Investments - Additional Information (Detail) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2023 USD ($) Security | Mar. 31, 2022 USD ($) | Dec. 31, 2022 USD ($)
Marketable Securities [Line Items] |  |  |
Individual fixed maturity held in unrealized loss position | Security | 170 |  |
Number of fixed maturity securities, allowance for credit loss | Security | 455 |  |
Fixed maturity securities, held-to-maturity, allowance for credit losses | $ 220 |  | $ 239
Available-for-sale, Allowance for Credit Losses | 0 |  | 0
Net realized gains on investments | 258 | $ 738 |
Net unrealized gains (losses) on equity securities | 1,369 | $ 1,040 |
Corporate Bonds [Member] |  |  |
Marketable Securities [Line Items] |  |  |
Fixed maturity securities, held-to-maturity, allowance for credit losses | $ 178 |  | 196
Number of majority securities | Security | 18 |  |
States and Political Subdivisions [Member] |  |  |
Marketable Securities [Line Items] |  |  |
Fixed maturity securities, held-to-maturity, allowance for credit losses | $ 40 |  | $ 40
Number of majority securities | Security | 434 |  |
Corporate Fixed Income Securities [Member] | Maximum [Member] |  |  |
Marketable Securities [Line Items] |  |  |
Investments maturity period using default rate | 20 years |  |

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