Income Taxes-Income Tax Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Provision at U.S. federal statutory tax rate	$ 47.4	$ 50.7	$ 39.4
State and local income taxes	(1.5)	(3.0)	(2.4)
Foreign tax rate differential	(25.7)	(21.7)	(23.9)
Permanent items	2.9	(2.3)	1.7
Unrecognized tax positions	(0.3)	5.6	14.7
Tax valuation allowance	3.1	7.2	(133.2)
Withholding Tax and other foreign taxes	(0.2)	0.6	1.4
Change in tax rate	2.0	(3.2)	1.3
Effective Income Tax Rate Reconciliation, Tax Effect of Other Comprehensive Income Deferred Taxes, Federal	0.0	0.0	2.7
Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount	(1.2)	(1.4)	(1.3)
Other	(0.7)	1.2	1.9
Total provision/(benefit)	$ 25.8	$ 33.7	$ (97.7)