Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		12 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Other comprehensive loss [Abstract]
Beginning balance		$ 490.1
Other comprehensive income (loss) before reclassifications		(44.7)	$ 35.9
Reclassifications for amortization of unrecognized net loss	[1]	5.4	5.6
Reclassifications for foreign currency translation losses	[2]	0.8
Reclassifications for realized gains (losses) - net	[3]	0.2	(0.1)
Income taxes		0.2	0.1
Total other comprehensive income (loss)		(38.1)	41.5
Ending balance		533.9	490.1
AIAC Air Conditioning South Africa Pty Ltd Member [Member]
Other comprehensive loss [Abstract]
Loss on write-off of accumulated foreign currency translation		(0.8)
Accumulated Other Comprehensive Loss [Member]
Other comprehensive loss [Abstract]
Beginning balance		(140.3)	(181.8)
Ending balance		(178.4)	(140.3)
Foreign Currency Translation [Member]
Other comprehensive loss [Abstract]
Beginning balance		(5.5)	(46.8)
Other comprehensive income (loss) before reclassifications		(37.9)	41.3
Reclassifications for amortization of unrecognized net loss	[1]	0.0	0.0
Reclassifications for foreign currency translation losses	[2]	0.8
Reclassifications for realized gains (losses) - net	[3]	0.0	0.0
Income taxes		0.0	0.0
Total other comprehensive income (loss)		(37.1)	41.3
Ending balance		(42.6)	(5.5)
Defined Benefit Plans [Member]
Other comprehensive loss [Abstract]
Beginning balance		(134.9)	(135.0)
Other comprehensive income (loss) before reclassifications		(7.1)	(5.7)
Reclassifications for amortization of unrecognized net loss	[1]	5.4	5.6
Reclassifications for foreign currency translation losses	[2]	0.0
Reclassifications for realized gains (losses) - net	[3]	0.0	0.0
Income taxes		0.3	0.2
Total other comprehensive income (loss)		(1.4)	0.1
Ending balance		(136.3)	(134.9)
Cash Flow Hedges [Member]
Other comprehensive loss [Abstract]
Beginning balance		0.1	0.0
Other comprehensive income (loss) before reclassifications		0.3	0.3
Reclassifications for amortization of unrecognized net loss	[1]	0.0	0.0
Reclassifications for foreign currency translation losses	[2]	0.0
Reclassifications for realized gains (losses) - net	[3]	0.2	(0.1)
Income taxes		(0.1)	(0.1)
Total other comprehensive income (loss)		0.4	0.1
Ending balance		$ 0.5	$ 0.1

[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 18 for additional information about the Company's pension plans.

[2] As a result of the sale of a business in South Africa during fiscal 2019, the Company wrote-off $0.8 million of accumulated foreign currency translation losses. See Note 1 for additional information about this transaction.

[3] Amounts represent net gains and losses associated with cash flow hedges that were reclassified to net earnings. See Note 19 for additional information regarding derivative instruments.