Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock at Cost [Member]	Treasury Stock Held for Deferred Compensaton [Member]	Additional Paid-in Capital [Member]	Foreign Currency Translation Adjustments [Member]	Unrealized Derivative Gains (Losses) [Member]	Minimum Retirement Benefit Liability Adjustments [Member]	Total Accumulated Other Comprehensive (Loss) Earnings [Member]	Deferred Compensation [Member]	Retained Earnings [Member]
Balances at Sep. 30, 2019	$ 1,726,741	$ 106	$ (602,098)	$ (9,382)	$ 207,120	$ (53,235)	$ (4,955)	$ (45,116)	$ (103,306)	$ 9,382	$ 2,224,919
Balance, Common Stock, shares at Sep. 30, 2019		72,960,000
Balance, Treasury Stock, shares at Sep. 30, 2019			(11,040,000)
Balance, Treasury stock held for deferred compensation, shares at Sep. 30, 2019				(211,000)
Net earnings	144,691										144,691
Other comprehensive earnings (loss), net of tax	35,930					(2,807)	37,626	1,111	35,930
Cash dividends paid	(27,525)										(27,525)
Purchases of treasury stock	(13,346)		$ (13,346)
Purchases of treasury stock, shares			(124,000)
Sales of treasury stock	12,725		$ 15,246		(2,521)
Sales of treasury stock, shares			363,000
Common shares issued from treasury stock for benefit plans	14,748		$ 5,328		9,420
Common shares issued from treasury stock for benefit plans, shares			124,000
Stock-based compensation	13,475				13,475
Purchases/transfers of stock by/to deferred compensation plan				$ (624)						624
Purchases and transfer of stock by/to deferred compensation plan, shares				(6,000)
Distribution of stock from deferred compensation plan				$ 43						(43)
Distribution of stock from deferred compensation plan, shares				1,000
Balances at Mar. 31, 2020	1,907,694	$ 106	$ (594,870)	$ (9,963)	227,494	(56,042)	32,671	(44,005)	(67,376)	9,963	2,342,340
Balance, Common Stock, shares at Mar. 31, 2020		72,960,000
Balance, Treasury Stock, shares at Mar. 31, 2020			(10,677,000)
Balance, Treasury stock held for deferred compensation, shares at Mar. 31, 2020				(216,000)
Balances at Dec. 31, 2019	1,798,603	$ 106	$ (592,596)	$ (9,911)	216,158	(43,467)	(4,575)	(45,506)	(93,548)	9,911	2,268,483
Balance, Common Stock, shares at Dec. 31, 2019		72,960,000
Balance, Treasury Stock, shares at Dec. 31, 2019			(10,814,000)
Balance, Treasury stock held for deferred compensation, shares at Dec. 31, 2019				(215,000)
Net earnings	91,318										91,318
Other comprehensive earnings (loss), net of tax	26,172					(12,575)	37,246	1,501	26,172
Cash dividends paid	(17,461)										(17,461)
Purchases of treasury stock	(13,346)		$ (13,346)
Purchases of treasury stock, shares			(124,000)
Sales of treasury stock	5,167		$ 5,744		(577)
Sales of treasury stock, shares			137,000
Common shares issued from treasury stock for benefit plans	14,748		$ 5,328		9,420
Common shares issued from treasury stock for benefit plans, shares			124,000
Stock-based compensation	2,493				2,493
Purchases/transfers of stock by/to deferred compensation plan				$ (81)						81
Purchases and transfer of stock by/to deferred compensation plan, shares				(1,000)
Distribution of stock from deferred compensation plan				$ 29						(29)
Balances at Mar. 31, 2020	1,907,694	$ 106	$ (594,870)	$ (9,963)	227,494	(56,042)	32,671	(44,005)	(67,376)	9,963	2,342,340
Balance, Common Stock, shares at Mar. 31, 2020		72,960,000
Balance, Treasury Stock, shares at Mar. 31, 2020			(10,677,000)
Balance, Treasury stock held for deferred compensation, shares at Mar. 31, 2020				(216,000)
Cumulative effect from adoption | ASC 842 [Member]	255										255
Balances at Sep. 30, 2020	$ 1,992,677	$ 106	$ (577,476)	$ (9,222)	231,936	(40,691)	(20,457)	(28,646)	(89,794)	9,222	2,427,905
Balance, Common Stock, shares at Sep. 30, 2020	72,960,000	72,960,000
Balance, Treasury Stock, shares at Sep. 30, 2020	(10,277,000)		(10,277,000)
Balance, Treasury stock held for deferred compensation, shares at Sep. 30, 2020	(199,000)			(199,000)
Net earnings	$ 109,883										109,883
Other comprehensive earnings (loss), net of tax	(13,647)					7,566	(21,286)	73	(13,647)
Cash dividends paid	(15,404)										(15,404)
Sales of treasury stock	28,454		$ 29,364		(910)
Sales of treasury stock, shares			695,000
Common shares issued from treasury stock for benefit plans	14,900		$ 5,358		9,542
Common shares issued from treasury stock for benefit plans, shares			128,000
Stock-based compensation	16,438				16,438
Purchases/transfers of stock by/to deferred compensation plan				$ (317)						317
Purchases and transfer of stock by/to deferred compensation plan, shares				(3,000)
Distribution of stock from deferred compensation plan				$ 436						(436)
Distribution of stock from deferred compensation plan, shares				10,000
Balances at Mar. 31, 2021	$ 2,133,301	$ 106	$ (542,754)	$ (9,103)	257,006	(33,125)	(41,743)	(28,573)	(103,441)	9,103	2,522,384
Balance, Common Stock, shares at Mar. 31, 2021	72,960,000	72,960,000
Balance, Treasury Stock, shares at Mar. 31, 2021	(9,454,000)		(9,454,000)
Balance, Treasury stock held for deferred compensation, shares at Mar. 31, 2021	(192,000)			(192,000)
Balances at Dec. 31, 2020	$ 2,063,462	$ 106	$ (565,095)	$ (9,485)	244,394	(19,452)	(31,495)	(29,369)	(80,316)	9,485	2,464,373
Balance, Common Stock, shares at Dec. 31, 2020		72,960,000
Balance, Treasury Stock, shares at Dec. 31, 2020			(9,992,000)
Balance, Treasury stock held for deferred compensation, shares at Dec. 31, 2020				(201,000)
Net earnings	68,313										68,313
Other comprehensive earnings (loss), net of tax	(23,125)					(13,673)	(10,248)	796	(23,125)
Cash dividends paid	(10,302)										(10,302)
Sales of treasury stock	17,084		$ 16,983		101
Sales of treasury stock, shares			410,000
Common shares issued from treasury stock for benefit plans	14,900		$ 5,358		9,542
Common shares issued from treasury stock for benefit plans, shares			128,000
Stock-based compensation	2,969				2,969
Purchases/transfers of stock by/to deferred compensation plan				$ (41)						41
Distribution of stock from deferred compensation plan				$ 423						(423)
Distribution of stock from deferred compensation plan, shares				9,000
Balances at Mar. 31, 2021	$ 2,133,301	$ 106	$ (542,754)	$ (9,103)	$ 257,006	$ (33,125)	$ (41,743)	$ (28,573)	$ (103,441)	$ 9,103	$ 2,522,384
Balance, Common Stock, shares at Mar. 31, 2021	72,960,000	72,960,000
Balance, Treasury Stock, shares at Mar. 31, 2021	(9,454,000)		(9,454,000)
Balance, Treasury stock held for deferred compensation, shares at Mar. 31, 2021	(192,000)			(192,000)