Changes in Unrecognized Tax Benefits (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011
Schedule of Unrecognized Tax Benefits [Line Items]
Beginning Balance	$ 22.0	$ 11.9	$ 7.1
Increases from Positions Taken During Prior Periods	0.9	10.1	1.9
Decreases from Positions Taken During Prior Periods	(14.2)	(3.5)	(1.3)
Increases from Positions Taken During the Current Period	0.3	3.5	4.2
Ending Balance	$ 9.0	$ 22.0	$ 11.9