Earnings Per Share - Reconciliation of Income from Operations Applicable to Common Shares and Computation of Diluted Weighted Average Shares Outstanding (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Feb. 28, 2013	Feb. 29, 2012
Numerator:
Net income (loss)	$ 1,191	$ (340)	$ 2,897	$ 252
Less: Allocation to participating securities	(4)		(10)	(1)
Net income (loss) applicable to common shares	$ 1,187	$ (340)	$ 2,887	$ 251
Denominator:
Weighted average common shares outstanding, basic	12,343	12,300	12,325	12,288
Dilutive stock options and awards	160		114	39
Weighted average common shares outstanding, diluted	12,503	12,300	12,439	12,327