v3.26.1
FAIR VALUE OF FINANCIAL INSTRUMENTS - Schedule of Fair Value of Assets and Liabilities (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Assets    
Total fixed maturities $ 517.1 $ 387.0
Cash equivalents 255.7 369.0
Restricted cash equivalents 61.8 19.0
Total assets at fair value 834.6 775.0
United States Treasury securities and agencies    
Assets    
Total fixed maturities 58.2 49.2
Municipal securities    
Assets    
Total fixed maturities 22.0 23.2
Corporate debt securities    
Assets    
Total fixed maturities 236.1 159.0
Asset-backed securities    
Assets    
Total fixed maturities 190.0 155.6
Total fixed maturities    
Assets    
Total fixed maturities 506.3 387.0
Short-term investments    
Assets    
Total fixed maturities 10.8  
Level 1    
Assets    
Cash equivalents 255.7 369.0
Restricted cash equivalents 61.8 19.0
Total assets at fair value 383.7 434.7
Level 1 | United States Treasury securities and agencies    
Assets    
Total fixed maturities 55.4 46.7
Level 1 | Municipal securities    
Assets    
Total fixed maturities 0.0 0.0
Level 1 | Corporate debt securities    
Assets    
Total fixed maturities 0.0 0.0
Level 1 | Asset-backed securities    
Assets    
Total fixed maturities 0.0 0.0
Level 1 | Total fixed maturities    
Assets    
Total fixed maturities 55.4 46.7
Level 1 | Short-term investments    
Assets    
Total fixed maturities 10.8  
Level 2    
Assets    
Cash equivalents 0.0 0.0
Restricted cash equivalents 0.0 0.0
Total assets at fair value 450.9 340.3
Level 2 | United States Treasury securities and agencies    
Assets    
Total fixed maturities 2.8 2.5
Level 2 | Municipal securities    
Assets    
Total fixed maturities 22.0 23.2
Level 2 | Corporate debt securities    
Assets    
Total fixed maturities 236.1 159.0
Level 2 | Asset-backed securities    
Assets    
Total fixed maturities 190.0 155.6
Level 2 | Total fixed maturities    
Assets    
Total fixed maturities 450.9 340.3
Level 2 | Short-term investments    
Assets    
Total fixed maturities 0.0  
Level 3    
Assets    
Cash equivalents 0.0 0.0
Restricted cash equivalents 0.0 0.0
Total assets at fair value 0.0 0.0
Level 3 | United States Treasury securities and agencies    
Assets    
Total fixed maturities 0.0 0.0
Level 3 | Municipal securities    
Assets    
Total fixed maturities 0.0 0.0
Level 3 | Corporate debt securities    
Assets    
Total fixed maturities 0.0 0.0
Level 3 | Asset-backed securities    
Assets    
Total fixed maturities 0.0 0.0
Level 3 | Total fixed maturities    
Assets    
Total fixed maturities 0.0 $ 0.0
Level 3 | Short-term investments    
Assets    
Total fixed maturities $ 0.0