| Taxes on Income - Summary of Components of the Company's Deferred Tax Assets (Detail) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | 
|---|---|---|
| Deferred tax assets: | ||
| Net operating loss carryforward | $ 37,636 | $ 20,453 | 
| Research and development costs carryforward | 15,997 | 13,835 | 
| Accrued Expenses | 446 | 198 | 
| Share-based compensation | 23 | 23 | 
| Other | 27 | 11 | 
| Gross deferred tax assets | 54,129 | 34,520 | 
| Valuation allowance | (54,117) | (34,520) | 
| Deferred tax liabilities: | ||
| Property and equipment | (12) | (11) | 
| Net deferred tax | $ 0 | $ 0 | 
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- References No definition available. 
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- References No definition available. 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible research tax credit carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from accrued liabilities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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