Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Feb. 28, 2017	Aug. 31, 2016
Current assets:
Allowance for doubtful accounts	$ 1.6	$ 1.7
Stockholders’ equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (shares)	50,000,000	50,000,000
Preferred stock, shares issued (shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (shares)	500,000,000	500,000,000
Common stock, shares issued (shares)	53,512,076	53,415,687
Treasury stock, shares (shares)	9,679,752	9,679,457