RESERVE FOR CLAIMS AND CLAIM EXPENSES - Narrative (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Liability for Catastrophe Claims [Line Items] | ||||
| Net claims and claim expenses incurred – prior accident years | $ (199,425) | $ (269,710) | $ (361,440) | $ (465,584) |
| Casualty and Specialty | ||||
| Liability for Catastrophe Claims [Line Items] | ||||
| Net claims and claim expenses incurred – prior accident years | 56,773 | $ (11,950) | ||
| Baltimore Bridge Collapse | Casualty and Specialty | ||||
| Liability for Catastrophe Claims [Line Items] | ||||
| Net claims and claim expenses incurred – prior accident years | $ 54,000 | |||