v3.26.1
Derivative Financial Instruments - Fair Value of Derivatives (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Derivatives, fair value disclosures    
Derivative instruments, assets $ 1,751.3 $ 1,224.5
Derivative instruments, liabilities (37.4) (671.2)
Fair value of embedded derivative liabilities reported with contractholder funds 2,142.5 1,410.2
Fair value of net (asset) liability embedded derivative reported with funds withheld payable (2,706.4) (2,633.4)
Derivatives designated as hedging instruments    
Derivatives, fair value disclosures    
Derivative instruments, assets 182.9 144.6
Derivative instruments, liabilities 184.6 208.6
Derivatives not designated as hedging instruments    
Derivatives, fair value disclosures    
Derivative instruments, assets 1,568.4 1,079.9
Derivative instruments, liabilities (222.0) (879.8)
Interest rate contracts | Derivatives designated as hedging instruments    
Derivatives, fair value disclosures    
Derivative instruments, liabilities 74.3 69.8
Interest rate contracts | Derivatives not designated as hedging instruments    
Derivatives, fair value disclosures    
Derivative instruments, assets 20.5 16.9
Derivative instruments, liabilities 136.0 136.0
Foreign exchange contracts | Derivatives designated as hedging instruments    
Derivatives, fair value disclosures    
Derivative instruments, assets 182.9 144.6
Derivative instruments, liabilities 110.3 138.8
Foreign exchange contracts | Derivatives not designated as hedging instruments    
Derivatives, fair value disclosures    
Derivative instruments, assets 73.1 70.3
Derivative instruments, liabilities 10.7 9.4
Equity contracts | Derivatives not designated as hedging instruments    
Derivatives, fair value disclosures    
Derivative instruments, assets 1,447.0 971.5
Derivative instruments, liabilities 185.8 191.6
Credit contracts | Derivatives not designated as hedging instruments    
Derivatives, fair value disclosures    
Derivative instruments, assets 27.8 21.2
Derivative instruments, liabilities 9.4 6.4
Other contracts | Derivatives not designated as hedging instruments    
Derivatives, fair value disclosures    
Derivative instruments, liabilities $ (563.9) $ (1,223.2)