Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Feb. 28, 2013	Feb. 29, 2012
Income Statement [Abstract]
Sales	$ 110,082	$ 103,477	$ 228,104	$ 211,645
Cost of sales	99,081	94,076	203,845	190,436
Gross margin	11,001	9,401	24,259	21,209
Operating expenses	7,171	6,434	14,944	12,543
Research and development expenses	1,300	1,317	2,765	2,657
Income from operations	2,530	1,650	6,550	6,009
Interest expense	(983)	(2,430)	(2,064)	(4,827)
Other non-operating income (expense), net	84	216	(79)	236
Income (loss) before income taxes	1,631	(564)	4,407	1,418
Income tax expense (benefit)	440	(224)	1,510	1,166
Net income (loss)	$ 1,191	$ (340)	$ 2,897	$ 252
Weighted average common shares and equivalents outstanding:
Basic	12,343	12,300	12,325	12,288
Diluted	12,503	12,300	12,439	12,327
Earnings (loss) per common share:
Basic earnings (loss) per share	$ 0.10	$ (0.03)	$ 0.23	$ 0.02
Diluted earnings (loss) per share	$ 0.10	$ (0.03)	$ 0.23	$ 0.02