v3.26.1
Fair Value Measurements - Quantitative Information for Level 3 Inputs (Details) - Market Yield - Significant Unobservable Inputs (Level 3)
$ in Millions
Jun. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
Senior Debt | Measurement Input, Discount Rate | Non-investment-grade | Minimum    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Debt instrument, measurement input 0.062 0.063
Senior Debt | Measurement Input, Discount Rate | Non-investment-grade | Maximum    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Debt instrument, measurement input 0.144 0.261
Senior Debt | Measurement Input, Discount Rate | Non-investment-grade | Weighted-average Yield    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Debt instrument, measurement input 0.093 0.091
Junior Debt | Measurement Input, Discount Rate | Non-investment-grade | Minimum    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Debt instrument, measurement input 0.073 0.085
Junior Debt | Measurement Input, Discount Rate | Non-investment-grade | Maximum    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Debt instrument, measurement input 0.260 0.260
Junior Debt | Measurement Input, Discount Rate | Non-investment-grade | Weighted-average Yield    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Debt instrument, measurement input 0.127 0.134
Investment-grade | Investment grade    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Assets, Fair Value Disclosure $ 117.2 $ 99.1
Investment-grade | Measurement Input, Discount Rate | Investment grade | Minimum    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Alternative investment, measurement input 0.048 0.016
Investment-grade | Measurement Input, Discount Rate | Investment grade | Maximum    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Alternative investment, measurement input 0.096 0.111
Investment-grade | Measurement Input, Discount Rate | Investment grade | Weighted-average Yield    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Alternative investment, measurement input 0.064 0.072
Senior Debt | Non-investment-grade    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Assets, Fair Value Disclosure $ 203.7 $ 102.6
Junior Debt | Non-investment-grade    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Assets, Fair Value Disclosure 31.2 35.2
Other    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Assets, Fair Value Disclosure 128.1 102.5
Investments in Fixed Maturities    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Assets, Fair Value Disclosure $ 480.2 $ 339.4