CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net income	$ 54,525	$ 13,737	$ 631
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	8,606	9,358	10,335
Gain on sale of division	0	(2,006)	0
Stock-based compensation	4,599	4,090	2,583
Bad debt expense, net	(54)	162	48
Deferred income taxes	(7,847)	(4,861)	(995)
Changes in operating assets and liabilities:
Accounts receivable, net	(99,718)	(31,629)	(7,509)
Contract assets and liabilities, net	227,598	3,122	(39,951)
Inventories	(13,276)	(21,426)	(599)
Income taxes	4,812	688	(473)
Prepaid expenses and other current assets	(3,253)	(2,577)	412
Accounts payable	(6,167)	18,594	9,760
Accrued liabilities	11,729	8,908	(3,151)
Other, net	999	258	(1,552)
Net cash provided by (used in) operating activities	182,553	(3,582)	(30,461)
Investing Activities:
Purchases of short-term investments	(33,515)	(22,381)	(27,735)
Maturities of short-term investments	14,748	26,320	27,688
Proceeds from sale of division	0	4,348	0
Purchases of property, plant and equipment	(7,819)	(2,451)	(2,931)
Proceeds from sale of property, plant and equipment	12	629	40
Proceeds from life insurance policy	0	0	474
Net cash provided by (used in) investing activities	(26,574)	6,465	(2,464)
Financing Activities:
Payments on industrial development revenue bonds	0	(400)	(400)
Shares withheld in lieu of employee tax withholding	(652)	(675)	(632)
Dividends paid	(12,407)	(12,233)	(12,142)
Net cash used in financing activities	(13,059)	(13,308)	(13,174)
Net increase (decrease) in cash, cash equivalents and restricted cash	142,920	(10,425)	(46,099)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	1,001	(1,935)	197
Cash, cash equivalents and restricted cash at beginning of period	101,954	114,314	160,216
Cash, cash equivalents and restricted cash at end of period	$ 245,875	$ 101,954	$ 114,314