v3.26.1
Segment Information - Financial Information By Reportable Segment (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Segment Reporting [Line Items]          
Identifiable assets $ 6,712.2   $ 6,712.2   $ 6,868.8
Capital expenditures 18.9 $ 10.9 37.4 $ 27.7  
Depreciation 14.8 14.6 29.4 29.4  
Operating Segments          
Segment Reporting [Line Items]          
Identifiable assets 6,315.8   6,315.8   6,425.4
Capital expenditures 17.9 9.8 32.9 22.8  
Depreciation 12.9 12.8 25.6 25.1  
Corporate and other          
Segment Reporting [Line Items]          
Identifiable assets 396.4   396.4   443.4
Capital expenditures 1.0 1.1 4.5 4.9  
Depreciation 1.9 1.8 3.8 4.3  
Flow | Operating Segments          
Segment Reporting [Line Items]          
Identifiable assets 1,308.9   1,308.9   1,640.2
Capital expenditures 3.3 2.2 6.1 5.1  
Depreciation 3.6 3.6 7.2 7.3  
Water Solutions | Operating Segments          
Segment Reporting [Line Items]          
Identifiable assets 3,250.8   3,250.8   2,900.9
Capital expenditures 5.9 3.8 10.7 7.5  
Depreciation 5.6 5.6 11.0 11.1  
Pool | Operating Segments          
Segment Reporting [Line Items]          
Identifiable assets 1,756.1   1,756.1   $ 1,884.3
Capital expenditures 8.7 3.8 16.1 10.2  
Depreciation $ 3.7 $ 3.6 $ 7.4 $ 6.7