Derivatives - Fair Value of Derivatives in Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Assets
Derivatives, reported in Short-term and other investments	$ 10.7	$ 16.8
Derivatives, reported in Short-term and other investments
Assets
Derivatives, reported in Short-term and other investments	10.7	16.8
FIA - embedded derivatives, reported in Other policyholder funds
Liabilities
Derivative liability	106.6	104.5
IUL - embedded derivatives, reported in Investment contract and policy reserves
Liabilities
Derivative liability	$ 2.1	$ 2.5