Derivatives and Hedging Activities - Summary of Effect of Derivative Instruments on Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Net sales	$ 641.4	$ 609.9	$ 556.5	$ 572.4	$ 618.0	$ 572.2	$ 487.8	$ 479.8	$ 2,380.2	$ 2,157.7	$ 1,797.6
Cost of sales									1,935.4	1,775.4	1,496.8
Interest expense									26.0	28.3	29.8
Amount of gain (loss) reclassified from AOCI to income									6.5	3.2	(21.9)
Net Sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)									1.0	(1.0)
Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)									5.1	3.8
Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)									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									5.1	3.8	(22.8)
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									1.0	(1.0)	0.5
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									0.2	(0.4)
Derivatives designated as hedging instruments									$ (0.2)	$ 0.4