Accumulated Other Comprehensive Loss - Schedule of Reclassifications of Recognized Transactions out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income, net	$ 0.7	$ (1.4)	$ (2.5)	$ 1.3
Reclassification out of Accumulated Other Comprehensive Income | Amortization of actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income, net	$ (0.3)	$ (0.2)	$ (0.6)	$ (0.4)