Geographic Regions (Parenthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue	$ 85,205	$ 65,463	$ 85,035
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue	58,937	48,089	65,942
United States | China Facility
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue	$ 19,700	$ 14,900	$ 17,400