v3.26.1
Schedule of Total Investment Return (Detail) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Investments, Debt and Equity Securities [Abstract]    
Net investment income $ 12,218 $ 14,782
Net realized investment gains (losses) (2,243) 136
Change in unrealized holding gains (losses) (3,293) 4,383
Net realized and unrealized investment returns (5,536) 4,519
Total investment return $ 6,682 $ 19,301
Total investment return % [1] 0.50% 1.30%
Average investment portfolio [2] $ 1,405,369 $ 1,436,218
[1] Not annualized.
[2] Average of total cash and invested assets, net of receivable/payable for securities, as of the beginning and end of the period.