Income Taxes - Schedule of Components of Income (Loss) Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Domestic	$ (18,652)	$ 916	$ 7,845
Foreign	3,673	(4,648)	(2,320)
Income (loss) before provision for income taxes	$ (14,979)	$ (3,732)	$ 5,525