v3.26.3
Segment Information - Financial Information By Reportable Segment (Detail) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Segment Reporting [Line Items]          
Identifiable assets $ 6,665.0   $ 6,665.0   $ 6,868.8
Capital expenditures 16.8 $ 17.4 54.2 $ 45.1  
Depreciation 15.3 15.3 44.7 44.7  
Operating Segments          
Segment Reporting [Line Items]          
Identifiable assets 6,279.2   6,279.2   6,425.4
Capital expenditures 14.2 16.9 47.1 39.7  
Depreciation 13.5 13.2 39.1 38.3  
Corporate and other          
Segment Reporting [Line Items]          
Identifiable assets 385.8   385.8   443.4
Capital expenditures 2.6 0.5 7.1 5.4  
Depreciation 1.8 2.1 5.6 6.4  
Flow | Operating Segments          
Segment Reporting [Line Items]          
Identifiable assets 1,312.6   1,312.6   1,640.2
Capital expenditures 4.0 2.9 10.1 8.0  
Depreciation 3.6 3.7 10.8 11.0  
Water Solutions | Operating Segments          
Segment Reporting [Line Items]          
Identifiable assets 3,221.6   3,221.6   2,900.9
Capital expenditures 5.0 6.0 15.7 13.5  
Depreciation 5.6 5.4 16.6 16.5  
Pool | Operating Segments          
Segment Reporting [Line Items]          
Identifiable assets 1,745.0   1,745.0   $ 1,884.3
Capital expenditures 5.2 8.0 21.3 18.2  
Depreciation $ 4.3 $ 4.1 $ 11.7 $ 10.8