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, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Goodwill
Goodwill, beginning balance	$ 168.8	$ 201.8	$ 176.5	$ 142.3
Acquisition of businesses			0.0	59.5
Dispositions			(6.7)	0.0
Attribution of acquisition date fair value estimates between goodwill and other intangible assets	0.0	(22.9)	0.0	(22.9)
Measurement period adjustments	0.0	(3.4)	(1.0)	(3.4)
Goodwill, ending balance	168.8	175.5	168.8	175.5
Other Intangible Assets
Other intangible assets (excluding goodwill), beginning balance	204.8	196.2	215.9	198.2
Acquisition of businesses			0.0	0.0
Dispositions			(6.9)	0.0
Attribution of acquisition date fair value estimates between goodwill and other intangible assets	0.0	22.9	0.0	22.9
Amortization	(1.5)	(1.4)	(5.7)	(3.4)
Other intangible assets (excluding goodwill), ending balance	203.3	217.7	203.3	217.7
Total Goodwill and Other Intangible Assets
Total Goodwill and Other Intangible Assets, beginning balance	373.6	398.0	392.4	340.5
Acquisition of businesses			0.0	59.5
Dispositions			(13.6)	0.0
Attribution of acquisition date fair value estimates between goodwill and other intangible assets	0.0	0.0	0.0	0.0
Measurement period adjustments	0.0	(3.4)	(1.0)	(3.4)
Amortization	(1.5)	(1.4)	(5.7)	(3.4)
Total Goodwill and Other Intangible Assets, ending balance	$ 372.1	$ 393.2	$ 372.1	$ 393.2