Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Operating Activities:
Net loss	$ (300)	$ (459)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	3,063	3,196
Amortization	88	88
Stock-based compensation	1,009	2,343
Bad debt expense (recovery)	(113)	248
Deferred income tax expense	(7)	48
Gain on amended supply agreement	(507)	(507)
Changes in operating assets and liabilities:
Accounts receivable, net	12,234	18,603
Costs and billings in excess of estimated earnings on uncompleted contracts	2,236	6,921
Inventories	2,444	(1,478)
Prepaid expenses and other current assets	(799)	(1,522)
Accounts payable and income taxes payable	(2,051)	(1,874)
Accrued liabilities	(13,398)	(1,898)
Other, net	(525)	356
Net cash provided by operating activities	3,374	24,065
Investing Activities:
Proceeds from sale of property, plant and equipment	0	12
Increase in short-term investments	(14,874)
Purchases of property, plant and equipment	(928)	(629)
Net cash used in investing activities	(15,802)	(617)
Financing Activities:
Payments on industrial development revenue bonds	(400)	(400)
Shares withheld in lieu of employee tax withholding	(398)	(795)
Purchase of treasury shares	0	(3,740)
Dividends paid	(2,966)	(2,992)
Net cash used in financing activities	(3,764)	(7,927)
Net increase (decrease) in cash and cash equivalents	(16,192)	15,521
Effect of exchange rate changes on cash and cash equivalents	(946)	(166)
Cash and cash equivalents, beginning of period	97,720	43,569
Cash and cash equivalents, end of period	$ 80,582	$ 58,924