Leases - Schedule of Financial Statement Classification of Lease Expenses Reported in Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee Lease Description [Line Items]
Total lease cost	$ 150	$ 83
Cost of sales
Lessee Lease Description [Line Items]
Operating lease cost	71	63
Finance lease cost	2	5
Short-term lease cost	27
Selling, general and administrative expenses
Lessee Lease Description [Line Items]
Operating lease cost	48	13
Finance lease cost	$ 2	$ 2