Supplemental Consolidated Cash and Cash Flow Information - Schedule of Cash and Restricted Cash (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Supplemental Cash Flow Elements [Abstract]
Cash	$ 26.2	$ 33.1	$ 29.0
Restricted cash	1.3	5.0	0.7
Total cash and restricted cash shown in the Consolidated Statements of Cash Flows	27.5	38.1	29.7	$ 42.8
Interest	32.2	33.5	30.1
Income taxes	$ 34.7	22.1	$ 14.0
Investments fixed maturity securities		$ 44.5