Investments - Net Unrealized 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] | ||||
| Unrealized gain (loss) on investments | $ (4,279) | $ 11,905 | $ (8,818) | $ 142,041 |
| Fixed maturities and short-term investments | ||||
| Marketable Securities [Line Items] | ||||
| Unrealized gain (loss) on investments | (6,529) | 28,782 | (47,171) | 63,269 |
| TS Hamilton Fund | ||||
| Marketable Securities [Line Items] | ||||
| Unrealized gain (loss) on investments | $ 2,250 | $ (16,877) | $ 38,353 | $ 78,772 |