Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Current federal	$ 0	$ 0	$ (4,641)
Current state	4,859	1,126	485
Deferred federal	47,239	20,331	20,639
Deferred state	1,173	89	1,490
Total expense	$ 53,271	$ 21,546	$ 17,973