Restructuring - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) Person	Dec. 31, 2015 USD ($) Person	Dec. 31, 2014 USD ($) Person
Restructuring Cost and Reserve [Line Items]
Number of employees | Person	650	500	550
Restructuring costs | $	$ 24.5	$ 41.3	$ 39.5
Water Quality Systems [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees | Person	100	100	50
Restructuring costs | $	$ 6.0	$ 6.2	$ 15.2
Flow & Filtration Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees | Person	200	200	350
Restructuring costs | $	$ 4.5	$ 11.2	$ 14.0
Technical Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees | Person	350	200	150
Restructuring costs | $	$ 12.3	$ 15.7	$ 4.3