Goodwill - Changes in Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022
Goodwill [Line Items]
Balance at January 1, 2022		$ 3,494.4
Acquisitions		3.7
Adjustments to purchase price allocations	$ 46.6	57.8
Divestitures		(159.7)
Goodwill reclassified from assets held for sale		4.3
Balance at June 30, 2022	3,400.5	3,400.5
East Group
Goodwill [Line Items]
Balance at January 1, 2022		759.4
Adjustments to purchase price allocations		5.0
Balance at June 30, 2022	764.4	764.4
West Group
Goodwill [Line Items]
Balance at January 1, 2022		2,735.0
Acquisitions		3.7
Adjustments to purchase price allocations		52.8
Divestitures		(159.7)
Goodwill reclassified from assets held for sale		4.3
Balance at June 30, 2022	$ 2,636.1	$ 2,636.1