Reclassifications from Accumulated Other Comprehensive (Loss) Income - Schedule of amounts reclassified from AOCI (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Amount reclassified from AOCI
Cost of sales									$ (1,535.0)	$ (1,908.4)	$ (1,774.1)
Net sales	$ 457.7	$ 456.3	$ 443.8	$ 455.6	$ 558.0	$ 570.6	$ 548.4	$ 549.8	1,813.4	2,226.7	2,173.0
Interest expense									(28.0)	(27.7)	(17.0)
Income before income taxes									21.5	89.1	196.4
Tax benefit									(10.2)	(30.4)	(63.6)
Net income	$ 14.9	$ (23.9)	$ 11.5	$ 8.9	$ 22.5	$ (1.4)	$ 24.1	$ 13.5	11.3	58.7	$ 132.8
Cash flow hedging items
Amount reclassified from AOCI
Net of tax									(27.5)	(9.9)
Cash flow hedging items | Amount Reclassified from AOCI
Amount reclassified from AOCI
Income before income taxes									(44.0)	(15.8)
Tax benefit									16.5	5.9
Net income									(27.5)	(9.9)
Cash flow hedging items | Amount Reclassified from AOCI | Commodity contracts
Amount reclassified from AOCI
Cost of sales									(44.6)	(18.5)
Cash flow hedging items | Amount Reclassified from AOCI | Foreign exchange contracts
Amount reclassified from AOCI
Net sales									0.2	2.3
Cash flow hedging items | Amount Reclassified from AOCI | Forward interest rate swaps
Amount reclassified from AOCI
Interest expense									0.4	0.4
Net actuarial loss
Amount reclassified from AOCI
Net actuarial loss									(30.1)	(18.7)
Prior service cost
Amount reclassified from AOCI
Net actuarial loss									6.1	(0.3)
Amortization of pension and other postretirement benefit plan items
Amount reclassified from AOCI
Net actuarial loss									(24.0)	(19.0)
Tax benefit									9.0	7.1
Net of tax									$ (15.0)	$ (11.9)