Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Changes in Goodwill
Goodwill, January 1	$ 9,734.3	$ 9,738.6
Goodwill, Acquisitions	30.6	212.8
Goodwill, Noncontrolling interests in acquired businesses	90.7	48.5
Goodwill, Contingent purchase price obligations of acquired businesses	170.1	8.7
Goodwill, Dispositions	(119.0)	(19.6)
Goodwill, Foreign currency translation	(17.3)	(489.3)
Goodwill, September 30	9,889.4	9,499.7
Goodwill, impairment losses	0.0	$ 0.0
Goodwill, accumulated impairment losses	0.0
Intangible assets:
Intangible assets, Gross Carrying Value	1,216.1		$ 1,133.3
Intangible assets, Accumulated Amortization	(831.2)		(819.9)
Intangible assets, Net Carrying Value	384.9		313.4
Purchased and internally developed software
Intangible assets:
Intangible assets, Gross Carrying Value	363.2		374.8
Intangible assets, Accumulated Amortization	(299.6)		(309.1)
Intangible assets, Net Carrying Value	63.6		65.7
Customer related and other
Intangible assets:
Intangible assets, Gross Carrying Value	852.9		758.5
Intangible assets, Accumulated Amortization	(531.6)		(510.8)
Intangible assets, Net Carrying Value	$ 321.3		$ 247.7