Income Taxes - Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Current income tax expense:
Federal	$ 2	$ 0
State	52	0
Total current income tax expense	54	0
Deferred income tax expense:
Federal	14,202	0
State	(1,240)	718
Total deferred income tax expense	12,962	718
Total income tax expense	$ 13,016	$ 718