Derivatives and Hedging Activities - Summary of effect of derivative instruments on income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Net sales	$ 351.9	$ 585.4	$ 1,054.0	$ 1,743.8
Cost of sales			1,029.1	1,409.0
Interest expense	8.9	4.9	23.5	15.6
Amount of gain reclassified from AOCI to income	1.5	2.4	6.9	10.7
Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain	0.0	0.1	0.0	0.7
Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain	1.4	2.2	6.6	9.7
Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Total gain	0.1	0.1	0.3	0.3
Commodity contracts | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	0.0	0.0	0.0	0.0
Commodity contracts | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	1.4	2.2	6.6	9.7
Commodity contracts | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	0.0	0.0	0.0	0.0
Foreign currency forward contracts | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	0.0	0.1	0.0	0.7
Foreign currency forward contracts | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	0.0	0.0	0.0	0.0
Foreign currency forward contracts | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	0.0	0.0	0.0	0.0
Interest Rate Swaps | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	0.0	0.0	0.0	0.0
Hedged Item	0.0	0.0	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0	0.0	0.0
Interest Rate Swaps | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	0.0	0.0	0.0	0.0
Hedged Item	0.0	0.0	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0	0.0	0.0
Interest Rate Swaps | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	0.1	0.1	0.3	0.3
Hedged Item	0.0	(0.6)	(2.7)	(0.7)
Derivatives designated as hedging instruments	$ 0.0	$ 0.6	$ 2.7	$ 0.7