SHAREHOLDERS' EQUITY (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Changes in shareholder's equity
Beginning Balance	$ 826,222
Net earnings common stockholders	86,777	$ 17,317
Ending Balance	915,491	776,792
Common Stock
Changes in shareholder's equity
Beginning Balance	306	305
Ending Balance	306	305
Common Stock Including Additional Paid in Capital
Changes in shareholder's equity
Beginning Balance	292,408	291,190
Stock compensation plans	(648)	1,103
Ending Balance	293,056	292,293
Retained Earnings
Changes in shareholder's equity
Beginning Balance	684,741	606,837
Net earnings common stockholders	86,777	17,317
Dividends paid	(2,079)	(2,073)
Adoption of accounting standards updates		5,589
Ending Balance	769,439	627,670
Accumulated other comprehensive income (loss)
Changes in shareholder's equity
Beginning Balance	(43,974)	(31,528)
Foreign currency translation	3,923	(4,529)
Forward exchange contracts		(25)
Ending Balance	(40,051)	(36,082)
Treasury Stock
Changes in shareholder's equity
Beginning Balance	(107,259)	(107,394)
Ending Balance	$ (107,259)	$ (107,394)

Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement.

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