Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating Activities:
Net income (loss)	$ (2,629)	$ 13,677
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	7,899	7,878
Stock-based compensation	2,135	2,391
Bad debt expense, net	194	187
Deferred income taxes	(586)	1,640
Changes in operating assets and liabilities:
Accounts receivable, net	(1,195)	14,268
Contract assets and liabilities, net	(35,673)	30,150
Inventories	991	(2,534)
Income taxes	(1,502)	(628)
Prepaid expenses and other current assets	1,490	1,071
Accounts payable	(2,202)	(11,264)
Accrued liabilities	(7,129)	(2,305)
Other, net	(1,486)	(1,131)
Net cash provided by (used in) operating activities	(39,693)	53,400
Investing Activities:
Purchases of short-term investments	(19,868)	(7,330)
Maturities of short-term investments	19,821	6,146
Purchases of property, plant and equipment, net	(2,440)	(4,274)
Proceeds from life insurance policies	474	0
Net cash used in investing activities	(2,013)	(5,458)
Financing Activities:
Payments on industrial development revenue bonds	(400)	(400)
Shares withheld in lieu of employee tax withholding	(632)	(617)
Dividends paid	(9,102)	(9,047)
Net cash used in financing activities	(10,134)	(10,064)
Net increase (decrease) in cash and cash equivalents	(51,840)	37,878
Effect of exchange rate changes on cash and cash equivalents	299	(491)
Cash and cash equivalents at beginning of period	160,216	118,639
Cash and cash equivalents at end of period	$ 108,675	$ 156,026