Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefits - beginning balance	$ 32,792	$ 30,921	$ 27,716
Decrease resulting from prior period tax positions	(721)		(26)
Increase resulting from prior period tax positions		671
Increase resulting from current period tax positions	20,612	1,200	3,231
Unrecognized tax benefits - ending balance	52,683	32,792	30,921
Less: deferred federal and state income tax benefits	(11,063)	(6,886)	(6,493)
Total unrecognized tax benefits that, if recognized, would impact the effective income tax rate as of the end of the year	$ 41,620	$ 25,906	$ 24,428