v3.25.4
STATUTORY REQUIREMENTS - Statutory Net Income (Loss) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Bermuda      
Statutory Accounting Practices [Line Items]      
Statutory Net Income (Loss) $ 2,759,822 $ 2,703,081 $ 2,699,083
Switzerland      
Statutory Accounting Practices [Line Items]      
Statutory Net Income (Loss) 357,358 411,526 225,751
U.K.      
Statutory Accounting Practices [Line Items]      
Statutory Net Income (Loss) 198,512 89,169 158,258
U.S.      
Statutory Accounting Practices [Line Items]      
Statutory Net Income (Loss) $ 42,277 $ (85,250) $ (17,618)