Revenue Recognition - Revenue Disaggregated by Customer Type (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 | Original equipment manufacturers/ end-users
Disaggregation of Revenue [Line Items]
Total									768.5	690.5	594.6
Process & Motion Control | Maintenance, repair, and operations
Disaggregation of Revenue [Line Items]
Total									612.1	550.7	540.1
Water Management
Disaggregation of Revenue [Line Items]
Total									670.3	610.4	577.8
Water Management | Water safety, quality, flow control and conservation
Disaggregation of Revenue [Line Items]
Total									624.4	566.9	538.9
Water Management | Water infrastructure
Disaggregation of Revenue [Line Items]
Total									$ 45.9	$ 43.5	$ 38.9