Accrued Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2020	Jun. 30, 2019
Accrued Liabilities, Current [Abstract]
Accrued compensation and benefits	$ 50.4	$ 71.2
Accrued pension liabilities	20.2	3.4
Accrued postretirement benefits	14.0	14.7
Deferred revenue	12.3	10.5
Short-term lease expense	11.5
Derivative financial instruments	11.1	16.7
Accrued interest expense	10.4	10.4
Accrued income taxes	1.0	4.2
Other	27.0	26.5
Total accrued liabilities	$ 157.9	$ 157.6
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent