SHAREHOLDERS' EQUITY (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Changes in shareholder's equity
Beginning balance	$ 1,131,142
Net earnings common stockholders	15,169	$ 14,727
Ending balance	1,154,094	1,066,398
Common stock
Changes in shareholder's equity
Beginning balance	308	307
Ending balance	308	307
Additional paid-in-capital
Changes in shareholder's equity
Beginning balance	304,850	301,553
Stock plans	433	(856)
Ending balance	305,283	300,697
Retained earnings
Changes in shareholder's equity
Beginning balance	989,315	905,022
Net earnings common stockholders	15,169	14,727
Cash dividends declared ($0.32 per share)	(2,064)	(2,067)
Ending balance	1,002,420	917,682
Accumulated other comprehensive income (loss)
Changes in shareholder's equity
Beginning balance	(23,969)	(31,764)
Foreign currency translation	9,414	11,513
Ending balance	(14,555)	(20,251)
Treasury stock
Changes in shareholder's equity
Beginning balance	(139,362)	(126,961)
Share repurchases		(5,076)
Ending balance	$ (139,362)	$ (132,037)