Reclassifications from Accumulated Other Comprehensive (Loss) Income - Schedule of Amounts Reclassified from AOCI (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Amount reclassified from AOCI
Cost of sales									$ 1,822.4	$ 1,935.4	$ 1,775.4
Net sales	$ 437.3	$ 585.4	$ 573.0	$ 585.4	$ 641.4	$ 609.9	$ 556.5	$ 572.4	2,181.1	2,380.2	2,157.7
Interest expense									19.8	26.0	28.3
Other income (expense), net									0.6	0.6	(0.8)
Tax expense									(4.6)	(49.0)	28.3
Net income	$ (118.4)	$ 39.9	$ 38.8	$ 41.2	$ 48.9	$ 51.1	$ 35.5	$ 31.5	1.5	167.0	$ 188.5
Cash flow hedging items | Amount Reclassified from AOCI
Amount reclassified from AOCI
Income before income taxes									12.7	6.5
Tax expense									(3.1)	(1.6)
Net income									9.6	4.9
Cash flow hedging items | Amount Reclassified from AOCI | Commodity contracts
Amount reclassified from AOCI
Cost of sales									11.5	5.1
Cash flow hedging items | Amount Reclassified from AOCI | Foreign exchange contracts
Amount reclassified from AOCI
Net sales									0.8	1.0
Cash flow hedging items | Amount Reclassified from AOCI | Forward interest rate swaps
Amount reclassified from AOCI
Interest expense									0.4	0.4
Net actuarial loss | Amount Reclassified from AOCI
Amount reclassified from AOCI
Other income (expense), net									(18.0)	(12.0)
Prior service cost | Amount Reclassified from AOCI
Amount reclassified from AOCI
Other income (expense), net									1.8	3.1
Pension and other postretirement benefit plan items | Amount Reclassified from AOCI
Amount reclassified from AOCI
Income before income taxes									(16.2)	(8.9)
Tax expense									3.9	2.1
Net income									$ (12.3)	$ (6.8)