Accrued Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jun. 30, 2018
Accrued Liabilities, Current [Abstract]
Accrued compensation and benefits	$ 71.2	$ 83.3
Derivative financial instruments	16.7	0.0
Accrued postretirement benefits	14.7	15.4
Deferred revenue	10.5	10.4
Accrued interest expense	10.4	10.4
Accrued income taxes	4.2	1.4
Accrued pension liabilities	3.4	3.3
Other	26.5	24.4
Total accrued liabilities	$ 157.6	$ 148.6