Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Operating Activities:
Net loss	$ (5,662)	$ (300)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	3,162	3,063
Amortization	73	88
Stock-based compensation	1,069	1,009
Bad debt recovery	(20)	(113)
Deferred income tax benefit	(1,292)	(7)
Gain on amended supply agreement	(507)	(507)
Changes in operating assets and liabilities:
Accounts receivable, net	(25,102)	12,234
Costs and billings in excess of estimated earnings on uncompleted contracts	23,155	2,236
Inventories	(88)	2,444
Income taxes	853	(1,319)
Prepaid expenses and other current assets	1,101	554
Accounts payable	(4,144)	(2,085)
Accrued liabilities	(6,673)	(13,398)
Other, net	15	(525)
Net cash provided by (used in) operating activities	(14,060)	3,374
Investing Activities:
Proceeds from sale of property, plant and equipment	55	0
Purchases of short-term investments	(20,712)	(14,874)
Maturities of short-term investments	24,425	0
Changes in restricted cash	(2,925)	0
Purchases of property, plant and equipment	(1,701)	(928)
Net cash used in investing activities	(858)	(15,802)
Financing Activities:
Payments on industrial development revenue bonds	(400)	(400)
Shares withheld in lieu of employee tax withholding	(438)	(398)
Dividends paid	(2,977)	(2,966)
Net cash used in financing activities	(3,815)	(3,764)
Net increase (decrease) in cash and cash equivalents	(18,733)	(16,192)
Effect of exchange rate changes on cash and cash equivalents	(39)	(946)
Cash and cash equivalents, beginning of period	68,359	97,720
Cash and cash equivalents, end of period	$ 49,587	$ 80,582