v3.26.3
Fair Value Measurements (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost $ 1,122.5  
Debt Securities, Available-for-sale 1,100.1  
Fair Value, Recurring    
Debt Securities, Available-for-sale [Line Items]    
Debt Securities, Available-for-sale 1,100.1 $ 939.6
Fair Value, Recurring | Corporate Debt Securities [Member]    
Debt Securities, Available-for-sale [Line Items]    
Debt Securities, Available-for-sale 499.9 451.9
Fair Value, Recurring | Municipal obligations [Member]    
Debt Securities, Available-for-sale [Line Items]    
Debt Securities, Available-for-sale 12.6 14.9
Fair Value, Recurring | US Government Sponsored Agencies [Member]    
Debt Securities, Available-for-sale [Line Items]    
Debt Securities, Available-for-sale 149.2 79.6
Fair Value, Recurring | Foreign Government Obligations [Member]    
Debt Securities, Available-for-sale [Line Items]    
Debt Securities, Available-for-sale 14.6 11.7
Fair Value, Recurring | Asset-backed Securities [Member]    
Debt Securities, Available-for-sale [Line Items]    
Debt Securities, Available-for-sale 423.8 381.5
Fair Value, Recurring | Location, Statement of Financial Position, Balance [Axis]: us-gaap:ShortTermInvestments    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 1,122.5 931.6
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0.2 8.8
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax (22.6) (0.8)
Debt Securities, Available-for-sale 1,100.1 939.6
Fair Value, Recurring | Location, Statement of Financial Position, Balance [Axis]: us-gaap:ShortTermInvestments | Corporate Debt Securities [Member]    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 510.4 447.4
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0.1 4.6
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax (10.6) (0.1)
Debt Securities, Available-for-sale 499.9 451.9
Fair Value, Recurring | Location, Statement of Financial Position, Balance [Axis]: us-gaap:ShortTermInvestments | Municipal obligations [Member]    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 12.8 14.6
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0.0 0.3
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax (0.2) 0.0
Debt Securities, Available-for-sale 12.6 14.9
Fair Value, Recurring | Location, Statement of Financial Position, Balance [Axis]: us-gaap:ShortTermInvestments | US Government Sponsored Agencies [Member]    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 151.9 79.1
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0.0 0.5
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax (2.7) 0.0
Debt Securities, Available-for-sale 149.2 79.6
Fair Value, Recurring | Location, Statement of Financial Position, Balance [Axis]: us-gaap:ShortTermInvestments | Foreign Government Obligations [Member]    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 14.6 11.6
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0.0 0.1
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax 0.0 0.0
Debt Securities, Available-for-sale 14.6 11.7
Fair Value, Recurring | Location, Statement of Financial Position, Balance [Axis]: us-gaap:ShortTermInvestments | Asset-backed Securities [Member]    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 432.8 378.9
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0.1 3.3
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax (9.1) (0.7)
Debt Securities, Available-for-sale $ 423.8 $ 381.5