EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended												12 Months Ended
	Aug. 31, 2015	May. 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May. 31, 2014	Feb. 28, 2014	Nov. 30, 2013	May. 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2013
Earnings Per Share [Abstract]
Net income from continuing operations	$ 22,447	$ 21,195	$ 24,835	$ 20,647	$ 21,856	$ 21,320	$ 28,278	$ 21,432	$ 18,539	$ 24,882	$ 20,005	$ 20,839	$ 89,124	$ 92,886	$ 84,265
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic													1,137	1,652	1,780
Net earnings available to common stockholders from continuing operations													$ 87,987	$ 91,234	$ 82,485
Basic weighted average shares outstanding													29,848	29,747	29,647
Add dilutive effect of stock options and restricted stock units (two-class method)													7	10	10
Diluted average shares outstanding													29,855	29,757	29,657
Basic income per share from continuing operations													$ 2.95	$ 3.07	$ 2.78
Diluted income per share from continuing operations													$ 2.95	$ 3.07	$ 2.78