Derivatives and Hedging Activities - Summary of effect of derivative instruments on income (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Net sales	$ 353.3	$ 585.4
Cost of sales	349.8	472.8
Interest expense	14.9	5.4
Amount of gain reclassified from AOCI to income	2.9	5.3
Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)	0.0	0.4
Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)	2.8	4.8
Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)	0.1	0.1
Commodity contracts | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	0.0	0.0
Commodity contracts | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	2.8	4.8
Commodity contracts | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	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	0.4
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
Foreign currency forward contracts | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain reclassified from AOCI to income	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
Hedged Item	0.0	0.0
Derivatives designated as hedging instruments	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
Hedged Item	0.0	0.0
Derivatives designated as hedging instruments	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
Hedged Item	(2.7)	0.0
Derivatives designated as hedging instruments	$ 2.7	$ 0.0