v3.26.1
Investments (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Schedule of Investments [Line Items]                
Impairments on investments $ 2.3 $ 2.9 $ 4.3 $ 2.9        
Allowance for credit losses 9.0 8.0 9.0 8.0 $ 8.5 $ 8.1 $ 5.7 $ 5.7
Federal Home Loan Bank of Boston [Member]                
Schedule of Investments [Line Items]                
Securities on loan, fair value 341.4   341.4     339.2    
Fixed Maturities [Member]                
Schedule of Investments [Line Items]                
Impairments on investments 1.0   1.5          
Mortgage Loans [Member]                
Schedule of Investments [Line Items]                
Impairments on investments 1.3 $ 2.6 2.8 $ 2.7        
Allowance for credit losses $ 9.0   $ 9.0     $ 8.1