Goodwill and Identifiable Assets Goodwill (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Roll Forward]
Gross goodwill, period start	$ 1,893.1	$ 1,894.1	$ 1,893.1	$ 1,894.1
Translation adjustment	(1.0)		1.4
Gross goodwill, period end			2,143.2	1,893.1	$ 1,894.1
Amortization of intangible assets			64.8	58.1	71.7
Commercial Business
Goodwill [Roll Forward]
Gross goodwill, period start	1,074.8	1,075.8	1,074.8	1,075.8
Translation adjustment		(1.0)	1.4
Gross goodwill, period end			1,324.9	1,074.8	1,075.8
Goodwill, Acquired During Period			248.7
Federal Government Business
Goodwill [Roll Forward]
Gross goodwill, period start	$ 818.3	$ 818.3	818.3	818.3
Gross goodwill, period end			$ 818.3	$ 818.3	$ 818.3