Income Taxes-Components of Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	$ 2.1	$ (0.6)	$ 0.0
State and local	(0.4)	(0.2)	(0.8)
Non-U.S.	22.7	26.3	31.9
Total	24.4	25.5	31.1
Deferred:
Federal	1.9	19.6	(125.3)
State and local	1.4	(4.8)	(1.1)
Non-U.S.	(1.9)	(6.6)	(2.4)
Total	1.4	8.2	(128.8)
Total provision/(benefit)	$ 25.8	$ 33.7	$ (97.7)