v3.26.3
Future Policy Benefits and Claims - Corporate (Details) - USD ($)
$ in Millions
 9 Months Ended 12 Months Ended
Sep. 30, 2026
Dec. 31, 2025
Present value of expected future policy benefit payments    
Future policy benefits $ 33,503.6 $ 39,993.8
Corporate | Long-term care insurance    
Present value of expected net premiums    
Balance at beginning of period, Present value of expected net premiums 32.4 30.8
Effect of changes in discount rate assumptions at beginning of period (2.0) (1.3)
Balance at beginning of period at original discount rate 30.4 29.5
Effect of changes in cash flow assumptions (2.3) 3.3
Effect of actual variances from expected experience (0.4) 0.3
Adjusted beginning of period balance at original discount rate 27.7 33.1
Interest accrual 1.2 1.8
Net premiums collected (3.5) (4.5)
Balance at end of period at original discount rate 25.4 30.4
Effect of changes in discount rate assumptions at end of period   2.0
Balance at end of period, Present value of expected net premiums 25.4 32.4
Present value of expected future policy benefit payments    
Balance at beginning of period, Present value of expected future policy benefit payments 199.1 195.6
Effect of changes in discount rate assumptions at beginning of period (12.7) (8.8)
Balance at beginning of period at original discount rate 186.4 186.8
Effect of changes in cash flow assumptions (12.3) 1.3
Effect of actual variances from expected experience 0.7 3.4
Adjusted beginning of period balance at original discount rate 174.8 191.5
Interest accrual 8.1 11.2
Benefit payments (12.2) (16.3)
Balance at end of period at original discount rate 170.7 186.4
Effect of changes in discount rate assumptions at end of period (3.2) 12.7
Balance at end of period, Present value of expected future policy benefit payments 167.5 199.1
Future policy benefits 142.1 166.7
Reinsurance impact $ (142.1) $ (166.7)
Weighted-average duration for future policy benefits (in years) 8 years 9 months 18 days 9 years 8 months 12 days