Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Operating Activities:
Net income (loss)	$ 29,657	$ (2,715)	$ 25,167
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	10,465	10,598	9,154
Amortization	2,612	4,848	4,549
Impairments		7,158	7,452
Stock-based compensation	1,723	99	1,929
Bad debt expense (recovery)	842	(114)	410
Deferred income taxes	(1,422)	(425)	(348)
Gain on sale of investment		(1,229)
Changes in operating assets and liabilities:
Accounts receivable, net	(16,209)	(17,616)	39,687
Costs and estimated earnings in excess of billings on uncompleted contracts	(34,755)	(13,519)	8,243
Inventories	3,948	1,542	12,320
Prepaid expenses and other current assets	4,821	4,514	(5,813)
Other assets	(13)	(2,627)	440
Accounts payable and income taxes payable	(6,036)	14,487	(20,281)
Accrued liabilities	6,411	(4,255)	(5,392)
Billings in excess of costs and estimated earnings on uncompleted contracts	(7,492)	13,553	(13,762)
Other, net	(517)	1,188	378
Net cash provided (used in) by operating activities	(5,965)	15,487	64,133
Investing Activities:
Proceeds from sale of property, plant and equipment	195	354	14
Purchases of property, plant and equipment	(29,063)	(7,347)	(4,420)
Proceeds from sale of investment		1,229
Decrease in cash held in escrow	1,000
Increase in cash held in escrow		(1,000)
Purchase of noncontrolling interest - Powell Asia			(659)
Acquisition of Powell Canada			(23,394)
Net cash used in investing activities	(27,868)	(6,764)	(28,459)
Financing Activities:
Borrowings on Canadian revolving line of credit	7,992	7,810	891
Payments on Canadian revolving line of credit	(7,992)	(7,818)	(13,984)
Payments on Canadian term loan			(2,429)
Payments on industrial development revenue bonds	(400)	(400)	(400)
Payments on deferred acquisition payable			(4,292)
Payments on short term and other financing	(717)	(1,068)	(1,087)
Proceeds from exercise of stock options	1,799	495	1,700
Tax benefit from exercise of stock options	589	180	209
Net cash provided by (used in) financing activities	1,271	(801)	(19,392)
Net increase (decrease) in cash and cash equivalents	(32,562)	7,922	16,282
Effect of exchange rate changes on cash and cash equivalents	(864)	191	1,668
Cash and cash equivalents at beginning of year	123,466	115,353	97,403
Cash and cash equivalents at end of year	$ 90,040	$ 123,466	$ 115,353