Derivatives - Fair Value of Derivatives in Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Short-term and other investments	Short-term and other investments
Assets
Derivatives, reported in Short-term and other investments	$ 6.8	$ 10.7
FIA - embedded derivatives, reported in Other policyholder funds
Liabilities
FIA - embedded derivatives, reported in Other policyholder funds	91.0	106.6
IUL - embedded derivatives, reported in Investment contract and policy reserves
Liabilities
IUL - embedded derivatives, reported in Investment contract and policy reserves	$ 1.2	$ 2.1