Income Taxes - Components of Income Taxes Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Current provision:
Federal	$ 9,315	$ 49,380	$ 38,028
Foreign	3,204	1,739	1,516
State	2,307	11,004	6,527
Total current provision	14,826	62,123	46,071
Deferred provision:
Federal	18,723	1,650	4,201
State	4,408	159	543
Total deferred provision	23,131	1,809	4,744
Total income tax provision	$ 37,957	$ 63,932	$ 50,815