Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		3 Months Ended
		Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Loss [Line Items]
Beginning balance		$ 414.0
Other comprehensive income (loss) before reclassifications		16.5	$ (4.8)
Reclassifications for amortization of unrecognized net loss	[1]	1.3	1.3
Income taxes		(0.5)	(0.4)
Total other comprehensive income (loss)		17.3	(3.9)
Ending balance		449.9
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Loss [Line Items]
Beginning balance		(181.8)	(174.2)
Ending balance		(164.5)	(178.1)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Loss [Line Items]
Beginning balance		(46.8)	(36.0)
Other comprehensive income (loss) before reclassifications		16.5	(4.8)
Reclassifications for amortization of unrecognized net loss	[1]	0.0	0.0
Income taxes		0.0	0.0
Total other comprehensive income (loss)		16.5	(4.8)
Ending balance		(30.3)	(40.8)
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Loss [Line Items]
Beginning balance		(135.0)	(138.2)
Other comprehensive income (loss) before reclassifications		0.0	0.0
Reclassifications for amortization of unrecognized net loss	[1]	1.3	1.3
Income taxes		(0.5)	(0.4)
Total other comprehensive income (loss)		0.8	0.9
Ending balance		$ (134.2)	$ (137.3)

[1] Amounts are included in the calculation of net periodic benefit cost for the Company's defined benefit plans, which include pension and other postretirement plans. See Note 4 for additional information about the Company's pension plans.