Reclassifications from Accumulated Other Comprehensive (Loss) Income (AOCI) - Schedule of amounts reclassified from AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	$ 349.8	$ 472.8
Net sales	353.3	585.4
Interest expense	14.9	5.4
(Loss) gain	(2.3)	(0.3)
(Loss) income before income taxes	(66.0)	54.1
Tax (expense)/benefit	18.9	(12.9)
Net (loss) income	(47.1)	41.2
Amount Reclassified from AOCI | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) income before income taxes	2.9	5.3
Tax (expense)/benefit	(0.7)	(1.3)
Net (loss) income	2.2	4.0
Amount Reclassified from AOCI | Net actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) gain	(5.2)	(4.5)
Amount Reclassified from AOCI | Prior service benefit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) gain	0.5	0.5
Amount Reclassified from AOCI | Pension and other postretirement benefit plan items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) income before income taxes	(4.7)	(4.0)
Tax (expense)/benefit	1.1	1.0
Net (loss) income	(3.6)	(3.0)
Amount Reclassified from AOCI | Commodity contracts | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	2.8	4.8
Amount Reclassified from AOCI | Foreign exchange contracts | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net sales	0.0	0.4
Amount Reclassified from AOCI | Forward interest rate swaps | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 0.1	$ 0.1