Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Condensed Consolidated Statements of Operations [Abstract]
Revenues	$ 141,369	$ 138,880	$ 391,153	$ 416,931
Cost of goods sold	119,505	100,636	318,548	304,337
Gross profit	21,864	38,244	72,605	112,594
Selling, general and administrative expenses	19,410	21,084	61,876	62,821
Amortization of intangible assets	1,237	1,132	3,658	3,193
Operating income	1,217	16,028	7,071	46,580
Other income			(1,229)
Interest expense	88	228	296	638
Interest income	(66)	(49)	(173)	(206)
Income before income taxes	1,195	15,849	8,177	46,148
Income tax provision	1,122	5,530	3,940	16,199
Net income	73	10,319	4,237	29,949
Net income attributable to noncontrolling interest		(33)		(159)
Net income attributable to Powell Industries, Inc.	$ 73	$ 10,286	$ 4,237	$ 29,790
Earnings per share attributable to Powell Industries, Inc.:
Basic	$ 0.01	$ 0.89	$ 0.36	$ 2.59
Diluted	$ 0.01	$ 0.88	$ 0.36	$ 2.56
Weighted average shares:
Basic	11,740	11,556	11,730	11,518
Diluted	11,812	11,679	11,806	11,648