Revenue Recognition - Revenue Disaggregated by Geography (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Total	$ 537.5	$ 485.0	$ 524.8	$ 503.6	$ 517.9	$ 436.7	$ 453.8	$ 443.2	$ 2,050.9	$ 1,851.6	$ 1,712.5
Process & Motion Control
Disaggregation of Revenue [Line Items]
Total									1,380.6	1,241.2	1,134.7
Process & Motion Control | United States and Canada
Disaggregation of Revenue [Line Items]
Total									898.7	848.3	795.0
Process & Motion Control | Europe
Disaggregation of Revenue [Line Items]
Total									327.5	255.5	218.9
Process & Motion Control | Rest of world
Disaggregation of Revenue [Line Items]
Total									154.4	137.4	120.8
Water Management
Disaggregation of Revenue [Line Items]
Total									670.3	610.4	577.8
Water Management | United States and Canada
Disaggregation of Revenue [Line Items]
Total									654.5	598.4	568.2
Water Management | Europe
Disaggregation of Revenue [Line Items]
Total									0.0	0.0	0.0
Water Management | Rest of world
Disaggregation of Revenue [Line Items]
Total									$ 15.8	$ 12.0	$ 9.6