Stock-Based Compensation - Additional Information (Detail) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares)	361,956	164,980
Weighted average exercise price (in usd per share)	$ 3.68	$ 7.16
Weighted average grant-date fair value of options granted (in usd per share)	$ 1.57	$ 4.58
Aggregate instrinsic value of options issued or exercised	$ 0	$ 0
Unrecognized stock-based compensation costs related to non-vested stock options	$ 197,162
Non-vested stock options (in shares)	361,956
Weighted average fair value of non-vested stock options (in usd per share)	$ 3.68
Weighted average period of recognition	9 months 18 days
Stock-based compensation expense	$ 599,117	$ 190,331
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	10 years	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%
2004 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period	10 years
Shares authorized (in shares)	439,890
Shares issued in period (in shares)	24,578
Shares outstanding (in shares)	361,956
Weighted average exercise price (in usd per share)	$ 3.68
Shares available for future grant (in shares)	53,356
2004 Stock Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
2009 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)	1,250
2004 Stock Plan and 2009 Inducement Plan \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of combined voting power of all classes of stock	10.00%
Percentage of fair value of common stock at date of grant	110.00%
2004 Stock Plan and 2009 Inducement Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	5 years
2010 ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued in period (in shares)	13,446	4,331
Shares outstanding (in shares)	0
Percentage of fair value of common stock at date of grant	85.00%
Maximum percentage of earnings employee can authorize to withhold, percentage	10.00%
Award vesting rights	All full-time employees and certain part-time employees are eligible to participate in the ESPP. For part-time employees to be eligible, they must have customary employment of more than five months in any calendar year and more than 20 hours per week. Employees who, after exercising their rights to purchase shares under the ESPP, would own shares representing 5% or more of the voting power of the Company’s common stock, are ineligible to participate.
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%
2010 ESPP \| Annual Fiscal First Day [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum	1.00%
2010 ESPP \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	3 years
2010 ESPP \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	5 years
2010 ESPP \| Maximum \| Annual Fiscal First Day [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized (in shares)	2,500
2004 and 2010 ESPPs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash received from option exercises and purchases	$ 23,436	$ 15,106

Percentage of combined voting power of all classes of stock.

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Percentage of fair market value.

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Share based compensation arrangement by share based payment award options nonvested weighted average price per shares.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cash inflow from issuance of shares under share-based payment arrangement. Includes, but is not limited to, option exercised.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Description of service or performance condition required to be met for earning right to award under share-based payment arrangement. Includes, but is not limited to, combination of market, performance or service condition.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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Number of additional shares authorized for issuance under share-based payment arrangement.

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Number of shares authorized for issuance under share-based payment arrangement.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

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Number of shares issued under share-based payment arrangement.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Number of non-vested options outstanding.

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