Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating Activities:
Net loss	$ (2,695)	$ (5,662)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	3,221	3,235
Stock-based compensation	1,221	1,069
Bad debt expense (recovery)	27
Bad debt expense (recovery)		(20)
Deferred income tax benefit	(517)	(1,292)
Gain on amended supply agreement	0	(507)
Changes in operating assets and liabilities:
Accounts receivable, net	4,385	(25,102)
Contract assets and liabilities, net	21,036	23,155
Inventories	(3,853)	(88)
Income taxes	6,620	853
Prepaid expenses and other current assets	(565)	1,101
Accounts payable	(8,622)	(4,144)
Accrued liabilities	(10,385)	(6,673)
Other, net	(764)	15
Net cash provided by (used in) operating activities	9,109	(14,060)
Investing Activities:
Purchases of short-term investments	(5,869)	(20,712)
Maturities of short-term investments	11,621	24,425
Purchases of property, plant and equipment	(764)	(1,701)
Proceeds from sale of property, plant and equipment	9	55
Net cash provided by investing activities	4,997	2,067
Financing Activities:
Payments on industrial development revenue bonds	(400)	(400)
Shares withheld in lieu of employee tax withholding	(731)	(438)
Dividends paid	(2,992)	(2,977)
Net cash used in financing activities	(4,123)	(3,815)
Net increase (decrease) in cash, cash equivalents and restricted cash	9,983	(15,808)
Effect of exchange rate changes on cash and cash equivalents	(813)	(39)
Cash, cash equivalents and restricted cash, beginning of period	61,725	93,210
Cash, cash equivalents and restricted cash, end of period	$ 70,895	$ 77,363