Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Changes in Goodwill
Goodwill, Beginning Balance	$ 10,082.3	$ 9,734.3
Goodwill, Acquisitions Of Controlling Interests	761.2	51.7
Goodwill, Acquisitions of noncontrolling interests	22.8	128.6
Goodwill, Contingent Purchase Price of Acquired Businesses	0.0	159.7
Goodwill, Written off Related to Sale of Business Unit	(6.0)	(120.6)
Goodwill, Foreign Currency Translation Gain (Loss)	(182.9)	128.6
Goodwill, Ending Balance	10,677.4	10,082.3	$ 9,734.3
Goodwill, impairment losses	0.0	0.0
Goodwill, accumulated impairment losses	0.0
Intangible assets:
Intangible assets, Gross Carrying Value	1,354.4	1,230.5
Intangible assets, Accumulated Amortization	(832.4)	(863.6)
Intangible assets, Net Carrying Value	522.0	366.9
Amortization of intangible assets	105.6	80.3	80.3
Acquired intangible assets and internally developed strategic platform assets
Intangible assets:
Intangible assets, Gross Carrying Value	1,096.1	902.6
Intangible assets, Accumulated Amortization	(606.1)	(572.9)
Intangible assets, Net Carrying Value	490.0	329.7
Amortization of intangible assets	87.5	61.8	58.8
Other purchased and internally developed software
Intangible assets:
Intangible assets, Gross Carrying Value	258.3	327.9
Intangible assets, Accumulated Amortization	(226.3)	(290.7)
Intangible assets, Net Carrying Value	32.0	37.2
Amortization of intangible assets	$ 18.1	$ 18.5	$ 21.5