Pension and Employee Benefit Plans, Defined Benefit Employee Benefit Plans (Details) - USD ($) $ in Millions		12 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	[1]	$ 2.9	$ 3.3	$ 2.9
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		13.9	16.0
Net periodic benefit cost		3.6	4.1	3.7
Pension Plans [Member] | U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		8.0	13.4	8.1
Pension Plans [Member] | No-U.S Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		5.9	2.6	1.4
Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost		$ 0.3	$ 0.2	$ 0.3

[1] Represents net periodic benefit cost, exclusive of service cost, for the Company's pension and postretirement plans.