Employee Benefit Plans - Schedule of Net Pension Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Retirement Benefits [Abstract]
Service costs	$ 1.7	$ 1.5	$ 2.2
Interest costs	0.9	1.1	1.0
Amortization of actuarial loss	0.8	0.4	0.8
Net pension period cost	$ 3.4	$ 3.0	$ 4.0