Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Changes in Goodwill
Goodwill, January 1	$ 9,734.3	$ 9,738.6
Goodwill, Acquisitions	51.7	211.7
Goodwill, Noncontrolling interests in acquired businesses	128.6	48.0
Goodwill, Contingent purchase price obligations of acquired businesses	159.7	8.7
Goodwill, Dispositions	(120.6)	(19.6)
Goodwill, Foreign currency translation	128.6	(253.1)
Goodwill, December 31	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	1,230.5	1,133.3
Intangible assets, Accumulated Amortization	(863.6)	(819.9)
Intangible assets, Net Carrying Value	366.9	313.4
Purchased and internally developed software
Intangible assets:
Intangible assets, Gross Carrying Value	369.1	374.8
Intangible assets, Accumulated Amortization	(306.6)	(309.1)
Intangible assets, Net Carrying Value	62.5	65.7
Customer related and other
Intangible assets:
Intangible assets, Gross Carrying Value	861.4	758.5
Intangible assets, Accumulated Amortization	(557.0)	(510.8)
Intangible assets, Net Carrying Value	$ 304.4	$ 247.7