Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating Activities:
Net income (loss)	$ (4,343)	$ 10,002
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	9,218	9,801
Amortization	263	263
Stock-based compensation	2,304	4,235
Bad debt expense (recovery)	(226)	221
Deferred income taxes	(915)	1,463
Gain on amended supply agreement	(1,522)	(1,522)
Cash received from amended supply agreement	2,333	2,333
Changes in operating assets and liabilities:
Accounts receivable, net	23,847	13,455
Costs and billings in excess of estimated earnings on uncompleted contracts	17,861	25,337
Inventories	7,519	4,639
Prepaid expenses and other current assets	(3,809)	597
Accounts payable and income taxes payable	(10,002)	(11,282)
Accrued liabilities	(14,017)	2,310
Other, net	(1,387)	(52)
Net cash provided by operating activities	27,124	61,800
Investing Activities:
Proceeds from sale of property, plant and equipment	11	122
Purchases of short-term investments	(60,018)	0
Maturities of short-term investments	4,654	0
Changes in restricted cash	(25,301)	0
Purchases of property, plant and equipment	(2,520)	(2,000)
Net cash used in investing activities	(83,174)	(1,878)
Financing Activities:
Payments on industrial development revenue bonds	(400)	(400)
Shares withheld in lieu of employee tax withholding	(398)	(1,000)
Purchase of treasury shares	0	(3,740)
Dividends paid	(8,904)	(8,882)
Net cash used in financing activities	(9,702)	(14,022)
Net increase (decrease) in cash and cash equivalents	(65,752)	45,900
Effect of exchange rate changes on cash and cash equivalents	516	(118)
Cash and cash equivalents, beginning of period	97,720	43,569
Cash and cash equivalents, end of period	$ 32,484	$ 89,351