Income Taxes - Schedule of components of the income tax expense (benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Federal	$ 810	$ 200	$ (55)
State and local	8,260	2,939	1,887
Total current	9,070	3,139	1,832
Federal	19,302	26,240	(7,408)
State and local	382	(711)	(2,702)
Total deferred	19,684	25,529	(10,110)
Income tax expense (benefit)	$ 28,754	$ 28,668	$ (8,278)