Derivatives and Hedging Activities - Summary of Effect of Derivative Instruments on Income (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
Derivative Instruments, Gain (Loss) [Line Items]
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
Cost of sales									1,822.4	1,935.4	1,775.4
Interest expense									19.8	26.0	28.3
Amount of gain (loss) reclassified from AOCI to income									12.7	6.5	3.2
Net Sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain									0.8	1.0
Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain									11.5	5.1
Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Total gain									0.4	0.4
Commodity Contract | Net Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income									0.0	0.0
Commodity Contract | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income									11.5	5.1	3.8
Commodity Contract | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income									0.0	0.0
Foreign Exchange Contract | Net Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income									0.8	1.0	(1.0)
Foreign Exchange Contract | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income									0.0	0.0
Foreign Exchange Contract | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income									0.0	0.0
Forward interest rate swaps | Net Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income									0.0	0.0
Hedged Item									0.0	0.0
Derivatives designated as hedging instruments									0.0	0.0
Forward interest rate swaps | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income									0.0	0.0
Hedged Item									0.0	0.0
Derivatives designated as hedging instruments									0.0	0.0
Forward interest rate swaps | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income									0.4	0.4	$ 0.4
Hedged Item									(1.4)	0.2
Derivatives designated as hedging instruments									$ 1.4	$ (0.2)