Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net earnings	$ 90,044	$ 29,606
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	28,825	29,304
Net (gain) loss on sales of assets	(9)	33
Stock-based compensation	4,937	11,316
Deferred income taxes	44
Changes in operating assets and liabilities:
Trade accounts receivable	6,430	31,318
Unbilled receivables (contract assets)	(27,154)	(12,226)
Costs to fulfill a contract	(1,580)	(496)
Inventories	(36,383)	(50,559)
Accounts payable and accrued liabilities	(31,654)	(30,412)
Contract liabilities	7,502	2,065
Income taxes	8,766	890
Retirement benefit obligations	(434)	(664)
Other	(2,545)	(4,773)
Net cash provided by operating activities	46,789	5,402
Cash flows from investing activities:
Payments for purchase of property, plant, and equipment	(41,812)	(24,390)
Proceeds from sale of assets and short-term investments	36	37
Business acquisition, net of cash acquired		878
Net cash (used in) investing activities	(41,776)	(23,475)
Cash flows from financing activities:
Cash dividends paid	(13,209)	(11,355)
Proceeds from sales of treasury stock	15,267	1,199
Payments for repurchases of common stock		(26,369)
Borrowings on revolving lines of credit and short-term borrowings	728,600	413,700
Payments on revolving lines of credit and short-term borrowings	(663,500)	(371,200)
Payments of long-term debt and finance lease obligations	(75,249)	(98)
Net cash (used in) provided by financing activities	(8,091)	5,877
Effect of exchange rate changes on cash and cash equivalents	9,979	3,687
Net change in cash and cash equivalents	6,901	(8,509)
Cash and cash equivalents at beginning of year	137,447	107,844
Cash and cash equivalents at end of period	$ 144,348	$ 99,335