Accrued Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2016	Jun. 30, 2016
Accrued Liabilities, Current [Abstract]
Accrued compensation and benefits	$ 43.0	$ 41.8
Derivative financial instruments	15.2	31.6
Accrued postretirement benefits	13.7	13.8
Accrued interest expense	11.3	11.2
Other	36.2	40.8
Total accrued liabilities	$ 119.4	$ 139.2