Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Research and development	$ 413	$ 631
Insurance	123	170
Other	377	368
Totals	$ 913	$ 1,169

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

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