Goodwill and Other Identifiable Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Roll Forward]
Beginning Balance	$ 3,274.6	$ 3,252.6
Acquisitions	56.6
Purchase accounting adjustments		(0.8)
Foreign  currency translation	(44.6)	22.8
Ending Balance	3,286.6	3,274.6
Flow
Goodwill [Roll Forward]
Beginning Balance	767.1	747.6
Acquisitions	0.0
Purchase accounting adjustments		0.0
Foreign  currency translation	(36.7)	19.5
Ending Balance	730.4	767.1
Water Solutions
Goodwill [Roll Forward]
Beginning Balance	1,400.6	1,398.1
Acquisitions	0.0
Purchase accounting adjustments		(0.8)
Foreign  currency translation	(7.9)	3.3
Ending Balance	1,392.7	1,400.6
Pool
Goodwill [Roll Forward]
Beginning Balance	1,106.9	1,106.9
Acquisitions	56.6
Purchase accounting adjustments		0.0
Foreign  currency translation	0.0	0.0
Ending Balance	$ 1,163.5	$ 1,106.9