Goodwill and Other Intangible Assets - Changes in Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Balance at beginning of period	$ 3,649.5	$ 3,494.4
Acquisitions		3.7
Goodwill reclassified from/(allocated to) assets held for sale	(260.0)	8.1
Divestitures		(159.7)
Goodwill Increased		303.0
Balance at end of period	3,389.5	3,649.5
East Group
Goodwill [Line Items]
Balance at beginning of period	764.4	759.4
Acquisitions		0.0
Goodwill reclassified from/(allocated to) assets held for sale	0.0	0.0
Divestitures		0.0
Goodwill Increased		5.0
Balance at end of period	764.4	764.4
West Group
Goodwill [Line Items]
Balance at beginning of period	2,885.1	2,735.0
Acquisitions		3.7
Goodwill reclassified from/(allocated to) assets held for sale	(260.0)	8.1
Divestitures		(159.7)
Goodwill Increased		298.0
Balance at end of period	$ 2,625.1	$ 2,885.1