Accrued Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2017	Jun. 30, 2016
Accrued Liabilities, Current [Abstract]
Accrued compensation and benefits	$ 59.1	$ 41.8
Accrued postretirement benefits	15.5	13.8
Derivative financial instruments	13.1	31.6
Accrued interest expense	11.2	11.2
Deferred revenue	9.8	8.9
Accrued income taxes	5.1	1.5
Accrued pension liabilities	3.3	10.1
Other	22.8	20.3
Total accrued liabilities	$ 139.9	$ 139.2