v3.25.2
Future Policy Benefits and Claims - Benefits and Protection (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Sep. 30, 2024
Jun. 30, 2025
Dec. 31, 2024
Present value of expected future policy benefit payments      
Future policy benefits   $ 38,285.0 $ 36,831.4
Benefits and Protection      
Present value of expected future policy benefit payments      
Future policy benefits   3,264.0 3,077.0
Benefits and Protection | Life Insurance | Term life      
Present value of expected net premiums      
Balance at beginning of period, Present value of expected net premiums   4,107.2 3,793.7
Effect of changes in discount rate assumptions at beginning of period   290.1 100.1
Balance at beginning of period at original discount rate   4,397.3 3,893.8
Effect of changes in cash flow assumptions     419.9
Effect of actual variances from expected experience   2.3 42.5
Adjusted beginning of period balance at original discount rate   4,399.6 4,356.2
Interest accrual   101.9 190.9
Net premiums collected   (206.1) (390.8)
Issuances   110.3 241.0
Balance at end of period at original discount rate   4,405.7 4,397.3
Effect of changes in discount rate assumptions at end of period   (222.4) (290.1)
Balance at end of period, Present value of expected net premiums   4,183.3 4,107.2
Present value of expected future policy benefit payments      
Balance at beginning of period, Present value of expected future policy benefit payments   5,355.2 4,879.6
Effect of changes in discount rate assumptions at beginning of period   366.0 124.5
Balance at beginning of period at original discount rate   5,721.2 5,004.1
Effect of changes in cash flow assumptions     488.1
Effect of actual variances from expected experience   (4.9) 45.1
Adjusted beginning of period balance at original discount rate   5,716.3 5,537.3
Interest accrual   133.5 247.9
Benefit payments   (168.7) (321.6)
Issuances   116.8 257.6
Balance at end of period at original discount rate   5,797.9 5,721.2
Effect of changes in discount rate assumptions at end of period   (265.6) (366.0)
Balance at end of period, Present value of expected future policy benefit payments   5,532.3 5,355.2
Future policy benefits   1,349.0 1,248.0
Reinsurance impact   23.2 19.5
Future policy benefits after reinsurance   $ 1,372.2 $ 1,267.5
Increase (decrease) in LFPB from actuarial assumptions $ 68.2    
Income before taxes, net of reinsurance increase (decrease) from actuarial assumptions (52.9)    
Weighted-average duration for future policy benefits (in years)   8 years 1 month 6 days 8 years 4 months 24 days
Benefits and Protection | Specialty Benefits | Individual disability      
Present value of expected net premiums      
Balance at beginning of period, Present value of expected net premiums   $ 2,680.6 $ 2,552.3
Effect of changes in discount rate assumptions at beginning of period   436.4 313.7
Balance at beginning of period at original discount rate   3,117.0 2,866.0
Effect of changes in cash flow assumptions     183.9
Effect of actual variances from expected experience   57.0 168.3
Adjusted beginning of period balance at original discount rate   3,174.0 3,218.2
Interest accrual   54.3 103.5
Net premiums collected   (147.5) (289.1)
Issuances   35.3 84.4
Balance at end of period at original discount rate   3,116.1 3,117.0
Effect of changes in discount rate assumptions at end of period   (386.5) (436.4)
Balance at end of period, Present value of expected net premiums   2,729.6 2,680.6
Present value of expected future policy benefit payments      
Balance at beginning of period, Present value of expected future policy benefit payments   4,509.6 4,450.7
Effect of changes in discount rate assumptions at beginning of period   1,302.8 903.5
Balance at beginning of period at original discount rate   5,812.4 5,354.2
Effect of changes in cash flow assumptions     216.2
Effect of actual variances from expected experience   57.1 173.2
Adjusted beginning of period balance at original discount rate   5,869.5 5,743.6
Interest accrual   106.3 203.3
Benefit payments   (112.4) (219.0)
Issuances   34.6 84.5
Balance at end of period at original discount rate   5,898.0 5,812.4
Effect of changes in discount rate assumptions at end of period   (1,253.4) (1,302.8)
Balance at end of period, Present value of expected future policy benefit payments   4,644.6 4,509.6
Future policy benefits   1,915.0 1,829.0
Reinsurance impact   (426.0) (412.1)
Future policy benefits after reinsurance   $ 1,489.0 $ 1,416.9
Increase (decrease) in LFPB from actuarial assumptions 32.3    
Income before taxes, net of reinsurance increase (decrease) from actuarial assumptions $ (18.2)    
Weighted-average duration for future policy benefits (in years)   17 years 8 months 12 days 18 years 3 months 18 days