Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net earnings		$ 109,883	$ 144,691
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization		65,556	65,476
Impairment of assets sold			37,902
Net gain on sales of assets and businesses	[1]	(1,942)	(13,557)
Stock-based compensation		16,438	13,475
Deferred income taxes		1,622	135
Changes in operating assets and liabilities:
Trade accounts receivable		(10,565)	(521)
Unbilled receivables (contract assets)		(32,565)	(50,624)
Costs to fulfill a contract		(9,226)	(15,064)
Inventories		16,877	(28,982)
Accounts payable and accrued liabilities		53,555	(78,878)
Contract liabilities		14,370	13,673
Income taxes		4,700	(30,331)
Retirement benefit obligations		(3,450)	(2,152)
Other		(6,256)	(3,064)
Net cash provided by operating activities		218,997	52,179
Cash flows from investing activities:
Payments for purchase of property, plant, and equipment		(13,313)	(29,361)
Proceeds from sale of assets		86	18,831
Proceeds from sales of short-term investments		16,566	12,684
Payments for purchases of short-term investments		(2,750)	(23)
Net cash provided by investing activities		589	2,131
Cash flows from financing activities:
Cash dividends paid		(15,404)	(27,525)
Proceeds from sales of treasury stock		28,454	12,726
Payments for repurchases of common stock			(13,346)
Borrowings on revolving lines of credit and short-term borrowings		74,400	788,306
Payments on revolving lines of credit and short-term borrowings		(74,400)	(807,869)
Payments of long-term debt and finance lease obligations		(100,835)	(754)
Net cash (used in) financing activities		(87,785)	(48,462)
Effect of exchange rate changes on cash and cash equivalents		2,524	(2,072)
Net change in cash and cash equivalents		134,325	3,776
Cash and cash equivalents, including restricted cash, at beginning of year		153,270	99,073
Cash and cash equivalents, including restricted cash, at end of period		$ 287,595	$ 102,849

[1] Included in net gain on sale of assets and businesses for the six-months ended March 31, 2020 was the pre-tax gain on sale of Duarte real property in the amount of $13,522 recognized in the first quarter of fiscal year 2020.