SHAREHOLDERS' EQUITY (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Changes in shareholder's equity
Beginning Balance			$ 1,019,696
Net earnings common stockholders	$ 23,173	$ 14,909	51,280	$ 43,131
Ending Balance	1,029,882	1,004,854	1,029,882	1,004,854
Common Stock
Changes in shareholder's equity
Beginning Balance	307	306	307	306
Stock plans		1		1
Ending Balance	307	307	307	307
Additional Paid-In Capital
Changes in shareholder's equity
Beginning Balance	298,353	295,796	297,644	293,682
Stock plans	1,510	782	2,219	2,896
Ending Balance	299,863	296,578	299,863	296,578
Retained Earnings
Changes in shareholder's equity
Beginning Balance	854,946	799,884	830,989	775,829
Net earnings common stockholders	23,173	14,909	51,280	43,131
Dividends paid	(2,069)	(2,084)	(6,219)	(6,251)
Ending Balance	876,050	812,709	876,050	812,709
Accumulated Other Comprehensive Income (Loss)
Changes in shareholder's equity
Beginning Balance	(7,472)	1,808	(2,161)	(3,657)
Foreign currency translation	(11,905)	535	(17,216)	6,000
Ending Balance	(19,377)	2,343	(19,377)	2,343
Treasury Stock
Changes in shareholder's equity
Beginning Balance	(124,961)	(107,134)	(107,083)	(107,134)
Issued under stock plans /(repurchased)	(2,000)	51	(19,878)	51
Ending Balance	$ (126,961)	$ (107,083)	$ (126,961)	$ (107,083)