Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net earnings	$ 372,971	$ 232,368	$ 171,698
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	116,170	119,743	120,628
Net (gain) loss on sales of assets and businesses	(457)	1,491	(1,775)
Stock-based compensation	33,052	23,383	20,109
Deferred income taxes	(44,606)	(40,155)	(23,226)
Changes in operating assets and liabilities:
Trade accounts receivable	35,799	(113,119)	(54,380)
Unbilled receivables (contract assets)	(51,168)	(23,879)	(44,451)
Costs to fulfill a contract	(3,718)	(11,544)	(17,118)
Inventories	(84,944)	3,234	(110,196)
Accounts payable and accrued liabilities	63,655	67,447	122,963
Contract liabilities	31,538	20,115	12,466
Income taxes	(18,069)	(3,652)	29,644
Retirement benefit obligations	(1,837)	(909)	(4,424)
Other	(9,297)	34,020	(28,300)
Net cash provided by operating activities	439,089	308,543	193,638
Cash flows from investing activities:
Payments for purchase of property, plant, and equipment	(96,280)	(76,500)	(52,868)
Proceeds from sale of assets	2,292	488	43
Proceeds from business divestiture	1,800		6,000
Payments for business acquisition, net of cash acquired		878	(21,549)
Proceeds from sales of short-term investments	9,738	7,692	12,557
Payments for purchases of short-term investments	(6,767)	(6,109)	(9,632)
Net cash used in investing activities	(89,217)	(73,551)	(65,449)
Cash flows from financing activities:
Cash dividends paid	(58,286)	(51,027)	(44,978)
Proceeds from sales of treasury stock	89,875	50,749	21,897
Payments for repurchases of common stock	(390,819)	(126,380)	(485,300)
Borrowings on revolving lines of credit and short-term borrowings	2,962,800	2,323,500	952,000
Payments on revolving lines of credit and short-term borrowings	(2,745,800)	(2,390,300)	(885,200)
Payments of debt financing costs		(2,236)
Payments of long-term debt and finance lease obligations	(75,817)	(779)	(797)
Net cash used in financing activities	(218,047)	(196,473)	(442,378)
Effect of exchange rate changes on cash and cash equivalents	12,998	(8,916)	(26,429)
Net change in cash and cash equivalents	144,823	29,603	(340,618)
Cash and cash equivalents at beginning of year	137,447	107,844	448,462
Cash and cash equivalents at end of year	$ 282,270	$ 137,447	$ 107,844