Segment Information - Financial Information By Reportable Segment (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Identifiable assets	[1]	$ 6,446.5	$ 6,563.3	$ 6,447.5
Capital expenditures		74.4	76.0	85.2
Depreciation		60.3	59.5	54.1
Operating Segments
Segment Reporting Information [Line Items]
Identifiable assets		6,005.5	6,084.7	6,219.1
Capital expenditures		59.5	59.9	77.5
Depreciation		51.6	50.6	46.8
Corporate and other
Segment Reporting Information [Line Items]
Identifiable assets	[1]	441.0	478.6	228.4
Capital expenditures		14.9	16.1	7.7
Depreciation		8.7	8.9	7.3
Flow | Operating Segments
Segment Reporting Information [Line Items]
Identifiable assets	[1]	1,590.7	1,709.7	1,722.4
Capital expenditures		20.1	19.6	24.0
Depreciation		21.4	21.1	19.5
Water Solutions | Operating Segments
Segment Reporting Information [Line Items]
Identifiable assets		2,613.5	2,695.2	2,786.4
Capital expenditures		22.3	23.0	24.7
Depreciation		17.1	18.1	18.4
Pool | Operating Segments
Segment Reporting Information [Line Items]
Identifiable assets	[1]	1,801.3	1,679.8	1,710.3
Capital expenditures		17.1	17.3	28.8
Depreciation		$ 13.1	$ 11.4	$ 8.9

[1] All cash and cash equivalents are included in “Corporate and other.”