SHAREHOLDERS' EQUITY (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Changes in shareholder's equity
Beginning Balance	$ 961,595
Net earnings common stockholders	13,686	$ 86,777
Ending Balance	979,599	915,491
Common Stock
Changes in shareholder's equity
Beginning Balance	306	306
Ending Balance	306	306
Additional paid-in-capital
Changes in shareholder's equity
Beginning Balance	293,682	292,408
Stock plans	1,053	648
Ending Balance	294,735	293,056
Retained Earnings
Changes in shareholder's equity
Beginning Balance	778,398	684,741
Net earnings common stockholders	13,686	86,777
Dividends paid	(2,084)	(2,079)
Ending Balance	790,000	769,439
Accumulated other comprehensive income (loss)
Changes in shareholder's equity
Beginning Balance	(3,657)	(43,974)
Foreign currency translation	5,349	3,923
Ending Balance	1,692	(40,051)
Treasury Stock
Changes in shareholder's equity
Beginning Balance	(107,134)	(107,259)
Ending Balance	$ (107,134)	$ (107,259)

Amount of paid and unpaid cash dividends declared for classes of stock, for example, but not limited to, common and preferred.

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Value, after forfeiture, of shares granted under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).

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