v3.26.1
Market Risk Benefits - Net Asset (Liability) Balances and Changes in Valuation of the MRBs for Individual Variable Annuities (Details) - USD ($)
$ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Net asset (liability) balances and the changes in the valuation of the MRBs    
Balance at beginning of period, market risk benefits $ 130.2  
Balance at end of period, market risk benefits 136.9 $ 130.2
Retirement and Income Solutions | Individual variable annuities    
Net asset (liability) balances and the changes in the valuation of the MRBs    
Balance at beginning of period, market risk benefits 130.2 137.4
Effect of changes in nonperformance risk at beginning of period 17.0 19.0
Adjusted balance at beginning of period, market risk benefits 147.2 156.4
Interest accrual and expected policyholder behavior (38.5) (62.8)
Benefit payments 0.3  
Changes in interest rates 15.2 13.0
Changes in equity markets 39.0 53.1
Changes in equity index volatility (11.6) (8.3)
Actual policyholder behavior different from expected behavior 1.5 (3.9)
Changes in other future expected assumptions   (0.3)
Adjusted balance at end of period, market risk benefits 153.1 147.2
Effect of changes in nonperformance risk at end of period (16.2) (17.0)
Balance at end of period, market risk benefits $ 136.9 $ 130.2
Weighted-average attained age of policyholders (years) 66 years 10 months 24 days 67 years
Net amount at risk $ 21.2 $ 29.3