Goodwill and Other Identifiable Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2025 USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 3,286.6
Foreign currency translation/other	77.7
Ending Balance	3,364.3
Flow
Goodwill [Roll Forward]
Beginning Balance	730.4
Foreign currency translation/other	63.6
Ending Balance	794.0
Water Solutions
Goodwill [Roll Forward]
Beginning Balance	1,392.7
Foreign currency translation/other	14.1
Ending Balance	1,406.8
Pool
Goodwill [Roll Forward]
Beginning Balance	1,163.5
Foreign currency translation/other	0.0
Ending Balance	$ 1,163.5