Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating Activities:
Net income	$ 14,203	$ 5,666
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	4,592	5,020
Amortization	835	1,413
Stock-based compensation	2,223	386
Bad debt expense (recoveries)	(380)	636
Deferred income taxes	39	304
Changes in operating assets and liabilities:
Accounts receivable, net	11,303	11,755
Costs and estimated earnings in excess of billings on uncompleted contracts	14,292	(25,911)
Inventories	498	(5,964)
Prepaid expenses and other current assets	(1,778)	6,391
Accounts payable and income taxes payable	302	4,632
Accrued liabilities	(10,172)	(4,925)
Billings in excess of costs and estimated earnings on uncompleted contracts	21,223	24,015
Other	(4)	(41)
Net cash provided by operating activities	57,176	23,377
Investing Activities:
Proceeds from sale of property, plant and equipment	639	70
Purchases of property, plant and equipment	(33,270)	(18,879)
Increase in cash held in escrow		(75)
Decrease in cash held in escrow		1,000
Net cash used in investing activities	(32,631)	(17,884)
Financing Activities:
Borrowings on Canadian revolving line of credit	2,375	7,352
Payments on Canadian revolving line of credit	(2,375)	(7,352)
Payments on industrial development revenue bonds	(400)	(400)
Payments on short term and other financing	(298)	19
Net cash used in financing activities	(698)	(381)
Net increase in cash and cash equivalents	23,847	5,112
Effect of exchange rate changes on cash and cash equivalents	175	(513)
Cash and cash equivalents, beginning of period	90,040	123,466
Cash and cash equivalents, end of period	$ 114,062	$ 128,065