Earnings Per Share (Details)	12 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Basic	29,389,000	30,978,000	27,746,000
Incremental shares from equity awards	160,000	163,000	230,000
Diluted	29,549,000	31,141,000	27,976,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	36,000	118,000	60,000
Special Stock Authorization Number Of Shares	1,000,000