Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2012	Jun. 30, 2011
Allowance for doubtful accounts	$ 6.5	$ 2.0
Preferred stock, shares authorized	25.0	25.0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	650.0	650.0
Common stock, shares issued	152.9	149.6
Common stock, shares outstanding	124.8	123.7
Treasury stock, shares	28.1	25.9