Contractual Commitments, Contingencies, and Off-Balance Sheet Arrangements - Contractual Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Data center expenses	$ 104.8	$ 106.0	$ 99.9
Facilities and equipment leases	50.3	38.1	36.5
Software license agreements	32.0	26.5	24.8
Software/hardware maintenance agreements	63.2	53.3	48.9
Total expenses	$ 250.3	$ 223.9	$ 210.1