v3.26.1
Investments - Aging of Gross Unrealized Losses (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Fair Value    
Less than 12 Months $ 447.5 $ 53.5
12 Months or More 4.9 4.9
Fair Value 452.4 58.4
Gross Unrealized Losses    
Less than 12 Months (2.2) 0.0
12 Months or More 0.0 0.0
Gross Unrealized Losses (2.2) 0.0
Corporate debt securities    
Fair Value    
Less than 12 Months 274.2 45.9
12 Months or More 4.9 4.9
Fair Value 279.1 50.8
Gross Unrealized Losses    
Less than 12 Months (1.3) 0.0
12 Months or More 0.0 0.0
Gross Unrealized Losses (1.3) 0.0
U.S. Government obligations    
Fair Value    
Less than 12 Months 131.7 0.4
12 Months or More 0.0 0.0
Fair Value 131.7 0.4
Gross Unrealized Losses    
Less than 12 Months (0.7) 0.0
12 Months or More 0.0 0.0
Gross Unrealized Losses (0.7) 0.0
Asset-backed securities    
Fair Value    
Less than 12 Months 19.4 0.0
12 Months or More 0.0 0.0
Fair Value 19.4 0.0
Gross Unrealized Losses    
Less than 12 Months (0.1) 0.0
12 Months or More 0.0 0.0
Gross Unrealized Losses (0.1) 0.0
Non-U.S. government obligations    
Fair Value    
Less than 12 Months 22.2 7.2
12 Months or More 0.0 0.0
Fair Value 22.2 7.2
Gross Unrealized Losses    
Less than 12 Months (0.1) 0.0
12 Months or More 0.0 0.0
Gross Unrealized Losses $ (0.1) $ 0.0