CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Aug. 31, 2016	Aug. 31, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 6,427	$ 9,033
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	129,060,664	129,060,664
Common stock, shares outstanding	114,635,596	115,635,338
Treasury stock, shares	14,425,068	13,425,326