Consolidated Statements of Income - (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Changes in Deferred Profit Liability	$ 84.2	$ 60.2	$ 80.7
Liability for Future Policy Benefit, Expected Future Policy Benefit, Period Increase (Decrease)	$ 33.5	$ 12.0	$ 30.2