Long-Duration Insurance Contracts - Market Risk Benefits by Asset and Liability Balance (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Market Risk Benefit [Line Items]
Net Liability	$ 1.3	$ 0.2	$ 4.0	$ 4.8	$ 8.6
Deferred variable annuities
Market Risk Benefit [Line Items]
Asset	4.2	4.4
Liability	5.5	4.7
Net Liability	$ 1.3	$ 0.3