v3.26.1
Reserves - Roll Forward of Claims and Benefits Payable (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]    
Claims and benefits payable, at beginning of period $ 2,101.2 $ 2,914.2
Less: Reinsurance ceded and other (899.0) (1,669.8)
Net claims and benefits payable, at beginning of period 1,202.2 1,244.4
Incurred losses and loss adjustment expenses related to:    
Current Year Claims and Claims Adjustment Expense 1,591.5 1,600.5
Prior years (74.1) (99.3)
Total incurred losses and loss adjustment expenses 1,517.4 1,501.2
Paid losses and loss adjustment expenses related to:    
Current year 928.2 943.9
Prior years 532.7 553.4
Total paid losses and loss adjustment expenses 1,460.9 1,497.3
Net claims and benefits payable, at end of period 1,258.7 1,248.3
Plus: Reinsurance ceded and other 850.9 1,102.6
Claims and benefits payable, at end of period 2,109.6 2,350.9
Ceded to U.S. Government | Not Rated    
Liability for Claims and Claims Adjustment Expense [Line Items]    
Reinsurance recoverables $ 160.5 $ 339.6