Reclassifications from Accumulated Other Comprehensive Loss - Schedule of amounts reclassified from AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 10.2	$ 6.7
(Loss) gain	4.1	(2.3)
Total before tax	(25.2)	(66.0)
Tax (expense)/benefit	10.4	18.9
Net loss	(14.8)	(47.1)
Amount Reclassified from AOCI | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(1.7)	2.9
Tax (expense)/benefit	0.4	(0.7)
Net loss	(1.3)	2.2
Amount Reclassified from AOCI | Pension and other postretirement benefit plan items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(1.5)	(4.7)
Tax (expense)/benefit	0.4	1.1
Net loss	(1.1)	(3.6)
Amount Reclassified from AOCI | Net actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) gain	(1.9)	(5.2)
Amount Reclassified from AOCI | Prior service benefit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) gain	0.4	0.5
Commodity contracts | Amount Reclassified from AOCI | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	(1.8)	2.8
Forward interest rate swaps | Amount Reclassified from AOCI | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 0.1	$ 0.1