Income Taxes (Schedule of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Reconciliation of gross unrecognized tax benefits [Roll Forward]
Balance at beginning of year	$ 29.5	$ 37.9
Increase in positions acquired in business combination	31.9	0.0
Increases in tax positions for prior years	0.4	0.8
Decreases in tax positions for prior years	0.0	(3.1)
Increases in tax positions for current year	5.6	2.9
Settlements	(4.2)	(0.2)
Lapse in statute of limitations	(3.0)	(8.8)
Balance at end of year	$ 60.2	$ 29.5