Pensions (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Periodic Benefit Cost [Abstract]
Net periodic benefit cost	[1]	$ 0.7	$ 0.7	$ 1.5	$ 1.4
Pension [Member]
Net Periodic Benefit Cost [Abstract]
Service cost		0.1	0.1	0.2	0.2
Interest cost		1.9	2.2	3.9	4.5
Expected return on plan assets		(2.8)	(2.9)	(5.7)	(5.9)
Amortization of unrecognized net loss		1.8	1.5	3.5	3.0
Net periodic benefit cost		1.0	$ 0.9	1.9	1.8
Pension [Member] | United States [Member]
Employer Contributions [Abstract]
Employer contributions				0.0	$ 1.7
Employer contributions expected to be contributed during fiscal 2021		$ 20.0		$ 20.0

[1] Net periodic benefit cost for the Company’s pension and postretirement plans is exclusive of service cost.