CONDENSED FINANCIAL INFORMATION OF REGISTRANT (PARENT COMPANY ONLY) - Schedule of Statements of Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Condensed Statement of Income Captions [Line Items]
Comprehensive income (loss)	$ 50,346	$ 38,593	$ 124,065	$ 23,821
Parent Company
Condensed Statement of Income Captions [Line Items]
Net income (loss) of subsidiaries	50,110	34,640	125,016	23,130
Comprehensive income (loss)	$ 50,346	$ 38,593	$ 124,065	$ 23,821