Restructuring - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) Person	Dec. 31, 2018 USD ($) Person	Dec. 31, 2017 USD ($) Person
Restructuring Cost and Reserve [Line Items]
Number of employees | Person	375	300	250
Restructuring costs	$ 14.0	$ 40.6	$ 28.2
Aquatic Systems
Restructuring Cost and Reserve [Line Items]
Restructuring costs	4.2	15.3	3.6
Filtration Solutions
Restructuring Cost and Reserve [Line Items]
Restructuring costs	4.7	14.6	13.0
Flow Technologies
Restructuring Cost and Reserve [Line Items]
Restructuring costs	2.7	9.3	7.0
Other
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 2.4	$ 1.4	$ 4.6