v3.22.2.2
Reserves - Roll Forward of Claims and Benefits Payable (Details) - USD ($)
$ in Millions
 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]    
Claims and benefits payable, at beginning of period $ 1,604.8 $ 1,619.9
Less: Reinsurance ceded and other (825.9) (850.5)
Net claims and benefits payable, at beginning of period 778.9 769.4
Incurred losses and loss adjustment expenses related to:    
Current year 1,728.0 1,714.8
Prior years 32.5 (30.6)
Total incurred losses and loss adjustment expenses 1,760.5 1,684.2
Paid losses and loss adjustment expenses related to:    
Current year 1,106.2 1,158.2
Prior years 449.8 447.7
Total paid losses and loss adjustment expenses 1,556.0 1,605.9
Net claims and benefits payable, at end of period 983.4 847.7
Plus: Reinsurance ceded and other 2,039.0 1,057.3
Claims and benefits payable, at end of period 3,022.4 1,905.0
Ceded to U.S. Government | Not Rated    
Paid losses and loss adjustment expenses related to:    
Reinsurance recoverables $ 960.4 $ 221.6