CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Operating Activities:
Net income	$ 631	$ 16,660	$ 9,890
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	10,335	10,538	12,032
Stock-based compensation	2,583	3,474	3,839
Bad debt expense	48	258	233
Deferred income taxes	(995)	1,473	820
Gain on cash surrender value of life insurance	0	(506)	0
Changes in operating assets and liabilities:
Accounts receivable, net	(7,509)	41,969	(20,193)
Contract assets and liabilities, net	(39,951)	12,546	55,333
Inventories	(599)	304	(7,989)
Income taxes	(473)	720	6,681
Prepaid expenses and other current assets	412	662	(2,626)
Accounts payable	9,760	(15,309)	9,550
Accrued liabilities	(3,151)	465	1,419
Other, net	(1,552)	(860)	(230)
Net cash provided by (used in) operating activities	(30,461)	72,394	68,759
Investing Activities:
Purchases of short-term investments	(27,735)	(18,553)	(5,869)
Maturities of short-term investments	27,688	6,146	13,088
Purchases of property, plant and equipment, net	(2,891)	(5,130)	(4,255)
Proceeds from life insurance policy	474	0	0
Net cash provided by (used in) investing activities	(2,464)	(17,537)	2,964
Financing Activities:
Payments on industrial development revenue bonds	(400)	(400)	(400)
Shares withheld in lieu of employee tax withholding	(632)	(629)	(1,454)
Dividends paid	(12,142)	(12,066)	(11,998)
Net cash used in financing activities	(13,174)	(13,095)	(13,852)
Net increase (decrease) in cash, cash equivalents and restricted cash	(46,099)	41,762	57,871
Effect of exchange rate changes on cash, cash equivalents and restricted cash	197	(185)	(957)
Cash, cash equivalents and restricted cash at beginning of period	160,216	118,639	61,725
Cash, cash equivalents and restricted cash at end of period	$ 114,314	$ 160,216	$ 118,639