Income Taxes - Components of Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Current:
U.S. Domestic	$ 138.2	$ 134.9	$ 120.8
Foreign	24.8	23.9	19.8
State	13.0	8.5	10.6
Total current	176.0	167.3	151.2
Deferred:
U.S. Domestic	(7.9)	(7.4)	4.5
Foreign	(4.2)	(0.4)	(0.9)
State	(2.5)	1.9	(3.0)
Total deferred	(14.7)	(5.9)	0.6
Total Provision for income taxes	$ 161.4	$ 161.4	$ 151.8