Long-Duration Insurance Contracts - Deferred Sale Inducement Costs, Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Movement in Deferred Sales Inducements [Roll Forward]
Balance, beginning of period	$ 14.1	$ 15.9
Capitalizations	0.0	0.0
Amortization expense	(1.0)	(1.0)
Experience adjustment	(0.3)	(0.8)
Balance, end of period	$ 12.8	$ 14.1