EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share [Abstract]
Net income	$ 335,627	$ 289,775	$ 264,724
Basic earnings per share
Weighted average shares of common stock outstanding-basic (in shares)	100,244	98,634	97,028
Basic earnings per common share (usd per share)	$ 3.35	$ 2.94	$ 2.73
Diluted earnings per share
Weighted average shares of common stock outstanding-basic (in shares)	100,244	98,634	97,028
Incremental shares (in shares)	544	655	599
Weighted average shares of common stock outstanding-diluted (in shares)	100,788	99,289	97,627
Diluted earnings per common share (usd per share)	$ 3.33	$ 2.92	$ 2.71