Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating Activities:
Net income (loss)	$ 2,775	$ (2,695)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	2,597	3,221
Stock-based compensation	982	1,220
Bad debt expense	42	27
Deferred income taxes	(126)	(517)
Changes in operating assets and liabilities:
Accounts receivable, net	11,844	4,385
Contract assets and liabilities, net	1,474	21,036
Inventories	(3,054)	(3,853)
Income taxes	216	6,620
Prepaid expenses and other current assets	498	(565)
Accounts payable	(5,457)	(8,622)
Accrued liabilities	(10,128)	(10,385)
Other, net	445	(763)
Net cash provided by operating activities	2,108	9,109
Investing Activities:
Purchases of short-term investments	0	(5,869)
Maturities of short-term investments	6,146	11,621
Purchases of property, plant and equipment, net	(2,402)	(755)
Net cash provided by investing activities	3,744	4,997
Financing Activities:
Payments on industrial development revenue bonds	(400)	(400)
Shares withheld in lieu of employee tax withholding	(611)	(731)
Dividends paid	(3,013)	(2,992)
Net cash used in financing activities	(4,024)	(4,123)
Net increase in cash, cash equivalents and restricted cash	1,828	9,983
Effect of exchange rate changes on cash, cash equivalents and restricted cash	499	(813)
Cash, cash equivalents and restricted cash at beginning of period	118,639	61,725
Cash, cash equivalents and restricted cash at end of period	$ 120,966	$ 70,895