Accrued Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Jun. 30, 2015
Accrued Liabilities, Current [Abstract]
Derivative financial instruments	$ 49.7	$ 32.7
Accrued compensation and benefits	40.3	44.3
Accrued postretirement benefits	14.0	14.0
Accrued interest expense	11.2	11.2
Accrued pension liabilities	3.4	3.3
Accrued income taxes	1.8	8.7
Other	35.2	38.4
Total accrued liabilities	$ 155.6	$ 152.6