Derivatives and Hedging Activities - Summary of effect of derivative instruments on income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Net sales	$ 609.9	$ 572.2	$ 1,738.8	$ 1,539.7
Cost of sales	486.7	476.2	1,416.9	1,272.3
Interest expense	7.1	7.5	20.3	22.0
Amount of gain (loss) reclassified from AOCI to income	2.4		1.4
Amount of gain (loss) reclassified from AOCI to income		2.1		(1.0)
Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)	0.2	(0.5)	0.8	(1.0)
Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)	2.1	2.5	0.3	(0.3)
Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)	0.1	0.1	0.3	0.3
Commodity contracts | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income	0.0		0.0
Amount of gain (loss) reclassified from AOCI to income		0.0
Commodity contracts | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income	2.1		0.3
Amount of gain (loss) reclassified from AOCI to income		2.5		(0.3)
Commodity contracts | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income	0.0		0.0
Amount of gain (loss) reclassified from AOCI to income		0.0
Foreign exchange contracts | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income	0.2		0.8
Amount of gain (loss) reclassified from AOCI to income		(0.5)		(1.0)
Foreign exchange contracts | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income	0.0		0.0
Amount of gain (loss) reclassified from AOCI to income		0.0
Foreign exchange contracts | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income	0.0		0.0
Amount of gain (loss) reclassified from AOCI to income		0.0
Interest Rate Swaps | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI to income	0.0		0.0
Amount of gain (loss) reclassified from AOCI to income		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 (loss) reclassified from AOCI to income	0.0		0.0
Amount of gain (loss) reclassified from AOCI to income		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 (loss) reclassified from AOCI to income	0.1		0.3
Amount of gain (loss) reclassified from AOCI to income		0.1		0.3
Hedged Item	0.2	0.1	0.5	(0.4)
Derivatives designated as hedging instruments	$ (0.2)	$ (0.1)	$ (0.5)	0.4
Amount Reclassified from AOCI | Accumulated Gain (Loss), Net Cash Flow Hedge, Parent | Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Net sales				0.0
Cost of sales				(0.3)
Interest expense				0.0
Amount Reclassified from AOCI | Accumulated Gain (Loss), Net Cash Flow Hedge, Parent | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Net sales				(1.0)
Cost of sales				0.0
Interest expense				0.0
Amount Reclassified from AOCI | Accumulated Gain (Loss), Net Cash Flow Hedge, Parent | Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net sales				0.0
Cost of sales				0.0
Interest expense				$ 0.3