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, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Amount reclassified from AOCI
Cost of sales									$ 1,513.3	$ 1,535.0	$ 1,908.4
Net sales	$ 507.7	$ 473.6	$ 427.4	$ 389.0	$ 457.7	$ 456.3	$ 443.8	$ 455.6	1,797.6	1,813.4	2,226.7
Interest expense									29.8	28.0	27.7
Income before income taxes									70.2	21.5	89.1
Tax benefit									(23.2)	(10.2)	(30.4)
Net income	$ 25.5	$ 20.7	$ 7.0	$ (6.2)	$ 14.9	$ (23.9)	$ 11.5	$ 8.9	47.0	11.3	$ 58.7
Cash flow hedging items
Amount reclassified from AOCI
Net of tax									(13.8)	(27.5)
Cash flow hedging items | Amount Reclassified from AOCI
Amount reclassified from AOCI
Income before income taxes									(21.9)	(44.0)
Tax benefit									8.1	16.5
Net income									(13.8)	(27.5)
Cash flow hedging items | Amount Reclassified from AOCI | Commodity contracts
Amount reclassified from AOCI
Cost of sales									(22.8)	(44.6)
Cash flow hedging items | Amount Reclassified from AOCI | Foreign exchange contracts
Amount reclassified from AOCI
Net sales									0.5	0.2
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									(41.0)	(30.1)
Prior service cost
Amount reclassified from AOCI
Net actuarial loss									4.7	6.1
Amortization of pension and other postretirement benefit plan items
Amount reclassified from AOCI
Net actuarial loss									(36.3)	(24.0)
Tax benefit									13.4	9.0
Net of tax									$ (22.9)	$ (15.0)