Fair Value on a Recurring and Nonrecurring Basis (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025	Dec. 31, 2024
Fair value assets and liabilities measured on recurring and nonrecurring basis
Long-term Debt, Fair Value		$ 2,727.5	$ 2,702.0
Discount rate floor contingent acquisition obligations		4.00%
Discount rate ceiling contingent acquisition obligations		6.00%
Level 1
Fair value assets and liabilities measured on recurring and nonrecurring basis
Cash equivalents		$ 673.6	1,139.5
Contingent acquisition obligations	[1]	0.0	0.0
Long-term Debt, Fair Value		0.0	0.0
Level 2
Fair value assets and liabilities measured on recurring and nonrecurring basis
Cash equivalents		0.0	0.0
Contingent acquisition obligations	[1]	0.0	0.0
Long-term Debt, Fair Value		2,727.1	2,701.6
Level 3
Fair value assets and liabilities measured on recurring and nonrecurring basis
Cash equivalents		0.0	0.0
Contingent acquisition obligations	[1]	5.5	5.5
Long-term Debt, Fair Value		0.4	0.4
Fair Value, Total [Member]
Fair value assets and liabilities measured on recurring and nonrecurring basis
Cash equivalents		673.6	1,139.5
Contingent acquisition obligations	[1]	5.5	5.5
Long-term Debt, Fair Value		$ 2,727.5	$ 2,702.0

[1] Contingent acquisition obligations includes deferred acquisition payments and unconditional obligations to purchase additional non-controlling equity shares of consolidated subsidiaries. Fair value measurement of the obligations is based upon actual and projected operating performance targets as specified in the related agreements. There was no change in this balance from December 31, 2024 to March 31, 2025. The amounts payable within the next twelve months are classified in accrued liabilities; any amounts payable thereafter are classified in other non-current liabilities.