Investments - Net Realized Gains (Losses) on Investments (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Marketable Securities [Line Items] | ||||
| Net realized gains (losses) on investments | $ 232,135 | $ 196,129 | $ 387,751 | $ 314,787 |
| Fixed maturities and short-term investments | ||||
| Marketable Securities [Line Items] | ||||
| Net realized gains (losses) on investments | (5,241) | 1,343 | (2,332) | 867 |
| TS Hamilton Fund | ||||
| Marketable Securities [Line Items] | ||||
| Net realized gains (losses) on investments | $ 237,376 | $ 194,786 | $ 390,083 | $ 313,920 |