v3.26.1
Fair Value of Financial Instruments - Schedule of Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities $ 144,624 $ 169,665
Equity securities 11,748 11,748
Contingent Receivable 11,923 9,955
Other investments 173,280 173,358
Total investments $ 341,575 $ 364,726
As a percentage of total assets 37.10% 36.10%
Underwriting-related derivative liability $ 9,236 $ 3,984
U.S. treasury bills    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 35,026 43,673
U.S. agency bonds – mortgage-backed    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 20,346 21,618
Non-U.S. government bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 52,827 30,295
Collateralized loan obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 27,518 62,624
Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 8,907 11,455
Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 0 0
Contingent Receivable 0 0
Other investments 0 0
Total investments $ 35,026 $ 43,673
As a percentage of total assets 3.80% 4.30%
Underwriting-related derivative liability $ 0 $ 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. treasury bills    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 35,026 43,673
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. agency bonds – mortgage-backed    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-U.S. government bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Collateralized loan obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Significant Other Observable Inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 4,838 4,838
Contingent Receivable 0 0
Other investments 0 0
Total investments $ 114,436 $ 130,830
As a percentage of total assets 12.40% 13.00%
Underwriting-related derivative liability $ 0 $ 0
Significant Other Observable Inputs (Level 2) | U.S. treasury bills    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Significant Other Observable Inputs (Level 2) | U.S. agency bonds – mortgage-backed    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 20,346 21,618
Significant Other Observable Inputs (Level 2) | Non-U.S. government bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 52,827 30,295
Significant Other Observable Inputs (Level 2) | Collateralized loan obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 27,518 62,624
Significant Other Observable Inputs (Level 2) | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 8,907 11,455
Significant Unobservable Inputs (Level 3)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 6,910 6,910
Contingent Receivable 11,923 9,955
Other investments 132,829 135,018
Total investments $ 151,662 $ 151,883
As a percentage of total assets 16.50% 15.00%
Underwriting-related derivative liability $ 9,236 $ 3,984
Significant Unobservable Inputs (Level 3) | U.S. treasury bills    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Significant Unobservable Inputs (Level 3) | U.S. agency bonds – mortgage-backed    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Significant Unobservable Inputs (Level 3) | Non-U.S. government bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Significant Unobservable Inputs (Level 3) | Collateralized loan obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Significant Unobservable Inputs (Level 3) | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities 0 0
Fair Value Based on NAV Practical Expedient    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other investments 40,451 38,340
Total investments $ 40,451 $ 38,340
As a percentage of total assets 4.40% 3.80%
Underwriting-related derivative liability $ 0 $ 0