Summary of Calculation of Realized Gains and Losses (Detail) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Investments, Debt and Equity Securities [Abstract] | ||||
| Net realized gains (losses) | $ 161 | $ 212 | $ 284 | $ 1,084 |
| Less: net gain (losses) recognized during the period on equity securities sold during the period | 0 | (255) | 0 | (266) |
| Unrealized gains (losses) recognized during the reporting period on equity securities still held | $ 161 | $ 467 | $ 284 | $ 1,350 |