Income Taxes - Components of Income Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Current:
Federal	$ (479)	$ (6,631)	$ 431
State and foreign	4,646	10,544	704
Total	4,167	3,913	1,135
Deferred:
Federal	3,202	(1,561)	(4,264)
State and foreign	81	(3,984)	5,535
Total	3,283	(5,545)	1,271
Total income tax expense (benefit)	$ 7,450	$ (1,632)	$ 2,406