Provision for Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands |
12 Months Ended | |
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Dec. 31, 2017 |
Dec. 31, 2016 |
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| Components of Deferred Tax Assets and Liabilities [Abstract] | ||
| Net operating loss carryforwards and credits | $ 13,844 | $ 11,401 |
| Stock-based compensation | 3,416 | |
| Accrued expenses | 445 | 301 |
| Research credits | 490 | |
| Other | 83 | 66 |
| Total deferred tax assets | 18,278 | 11,768 |
| State taxes | 6 | 6 |
| Convertible note payable | (1,823) | |
| Stock-based compensation | (94) | |
| Total deferred tax liabilities | (1,917) | |
| Valuation allowance | (18,278) | (9,851) |
| Total deferred tax liabilities | $ 0 | $ 0 |
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- References No definition available.
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- Definition Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of deferred tax liability attributable to taxable temporary differences. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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/presentationRef
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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/2003/role/presentationRef
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- Definition Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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://www.xbrl.org/2003/role/presentationRef
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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/2003/role/presentationRef
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from reserves and accruals. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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/presentationRef
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- Definition Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of deferred tax liability attributable to taxable temporary differences from financing arrangements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Deferred Tax Liabilities Stock Based Compensation Plans No definition available.
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