Restructuring and Other Similar Charges - By Operating Segment (Details) - USD ($) $ in Millions	12 Months Ended			108 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2020
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	$ 15.5	$ 12.1	$ 14.1	$ 110.8
Employee termination benefits
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	13.3	7.1	5.2	78.5
Asset impairment charges
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs		0.3	0.8	3.6
Contract termination and other associated costs
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	2.2	4.7	8.1	28.7
Operating Segments | Process & Motion Control
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	14.3	7.9	13.3	92.1
Operating Segments | Process & Motion Control | Employee termination benefits
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	12.7	5.6	4.6	67.2
Operating Segments | Process & Motion Control | Asset impairment charges
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs		0.3	0.8	3.6
Operating Segments | Process & Motion Control | Contract termination and other associated costs
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	1.6	2.0	7.9	21.3
Operating Segments | Water Management
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	1.0	1.2	0.8	13.5
Operating Segments | Water Management | Employee termination benefits
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	0.5	0.9	0.6	8.6
Operating Segments | Water Management | Asset impairment charges
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs		0.0	0.0	0.0
Operating Segments | Water Management | Contract termination and other associated costs
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	0.5	0.3	0.2	4.9
Corporate
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	0.2	3.0	0.0	5.2
Corporate | Employee termination benefits
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	0.1	0.6	0.0	2.7
Corporate | Asset impairment charges
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs		0.0	0.0	0.0
Corporate | Contract termination and other associated costs
Restructuring Cost and Reserve [Line Items]
Total restructuring and other similar costs	$ 0.1	$ 2.4	$ 0.0	$ 2.5