Goodwill and Other Intangible Assets - Schedule of Goodwill and Other Intangible Assets Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Goodwill
Goodwill, beginning balance	$ 439.2	$ 168.8	$ 168.8	$ 176.5
Acquisition of businesses			270.4	0.0
Dispositions			0.0	(6.7)
Measurement period adjustments			0.0	(1.0)
Goodwill, ending balance	439.2	168.8	439.2	168.8
Other Intangible Assets
Other intangible assets (excluding goodwill), beginning balance	291.8	204.8	201.8	215.9
Acquisition of businesses			101.0	0.0
Acquisition of intangible assets			0.3	0.0
Dispositions			0.0	(6.9)
Amortization	(5.3)	(1.5)	(16.6)	(5.7)
Other intangible assets (excluding goodwill), ending balance	286.5	203.3	286.5	203.3
Total Goodwill and Other Intangible Assets
Total Goodwill and Other Intangible Assets, beginning balance	731.0	373.6	370.6	392.4
Acquisition of businesses			371.4	0.0
Acquisition of intangible assets			0.3	0.0
Dispositions			0.0	(13.6)
Measurement period adjustments			0.0	(1.0)
Amortization	(5.3)	(1.5)	(16.6)	(5.7)
Total Goodwill and Other Intangible Assets, ending balance	$ 725.7	$ 372.1	$ 725.7	$ 372.1