Supplemental Balance Sheet Information - Summary of Prepaids and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Prepaid Expense And Other Assets Current [Abstract]
Prepaid expenses	$ 2,972	$ 1,712
Irish research and development credits receivable	1,140	1,164
CARES Act employee retention credit receivable	3,577	3,577
Prepaids and other	$ 7,689	$ 6,453

Amount of asset related to consideration paid in advance for costs that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

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Name:	us-gaap_PrepaidExpenseCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant