v3.26.3
Fair Value - Assets Measured on a Recurring Basis (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in equity securities $ 1,263,521 $ 0
Short-term investments 27,761 0
Investments in fixed maturity securities 11,036 0
Derivative assets 18,948 3,113
Derivative liabilities 0 689
U.S. Government    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 3,137 0
U.S. Corporate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 7,297 0
Foreign Governments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 602 0
Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in equity securities 1,263,521 0
Short-term investments 0 0
Derivative assets 0 0
Derivative liabilities 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Corporate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign Governments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 0 0
Significant Other Observable Inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in equity securities 0 0
Short-term investments 27,761 0
Derivative assets 18,740 3,113
Derivative liabilities 0 689
Significant Other Observable Inputs (Level 2) | U.S. Government    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 3,137 0
Significant Other Observable Inputs (Level 2) | U.S. Corporate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 7,297 0
Significant Other Observable Inputs (Level 2) | Foreign Governments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 602 0
Significant Unobservable Inputs (Level 3)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in equity securities 0 0
Short-term investments 0 0
Derivative assets 208 0
Derivative liabilities 0 0
Significant Unobservable Inputs (Level 3) | U.S. Government    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 0 0
Significant Unobservable Inputs (Level 3) | U.S. Corporate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 0 0
Significant Unobservable Inputs (Level 3) | Foreign Governments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities $ 0 $ 0