v3.26.1
Realized and Net Change in Unrealized Gains (Losses) in Other Investments (Detail) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Gain (Loss) on Securities [Line Items]    
Total Investment Income $ 1,144,643 $ 1,169,506
Other Investments    
Gain (Loss) on Securities [Line Items]    
Realized Gains 3,780 112,648
Net Change in Unrealized Gains (Losses) (314,929) 172,432
Total Investment Income $ (311,149) $ 285,080