Reclassifications from Accumulated Other Comprehensive Loss - Schedule of amounts reclassified from AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net	$ 11.2	$ 8.9	$ 31.5	$ 23.5
(Loss) gain	1.8	(8.3)	12.5	(9.4)
Total before tax	(8.3)	(57.2)	(68.5)	(218.9)
Tax (expense)/benefit	0.8	16.7	16.8	46.4
Net loss	(7.5)	(40.5)	(51.7)	(172.5)
Amount Reclassified from AOCI | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(2.4)	1.5	(5.2)	6.9
Tax (expense)/benefit	0.5	(0.4)	1.3	(1.7)
Net loss	(1.9)	1.1	(3.9)	5.2
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)	(13.1)	(4.5)	(22.4)
Tax (expense)/benefit	0.4	1.4	1.2	3.5
Net loss	(1.1)	(11.7)	(3.3)	(18.9)
Amount Reclassified from AOCI | Net actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) gain	(1.9)	(4.7)	(5.7)	(15.1)
Amount Reclassified from AOCI | Prior service benefit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) gain	0.4	0.5	1.2	1.6
Amount Reclassified from AOCI | Settlement charge
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) gain	0.0	(8.9)	0.0	(8.9)
Commodity contracts | Amount Reclassified from AOCI | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	(2.5)	1.4	(5.4)	6.6
Forward interest rate swaps | Amount Reclassified from AOCI | Cash flow hedging items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net	$ 0.1	$ 0.1	$ 0.2	$ 0.3