v3.25.2
Separate Account Balances - Benefits and Protection (Details) - USD ($)
$ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2025
Dec. 31, 2024
Changes in separate account liabilities    
Balance at beginning of period $ 173,327.1  
Balance at end of period 180,728.0 $ 173,327.1
Benefits and Protection | Life Insurance | Universal life    
Changes in separate account liabilities    
Balance at beginning of period 6,806.7 5,982.5
Premiums and deposits 355.8 557.2
Policy charges (67.6) (132.7)
Surrenders, withdrawals and benefit payments (197.4) (492.2)
Investment performance 436.4 880.5
Net transfers (to) from general account 4.0 11.4
Balance at end of period 7,337.9 6,806.7
Cash surrender value $ 7,407.6 $ 6,869.5