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Stock Based Compensation - Additional Information (Detail) - USD ($) |  |  | 12 Months Ended |
--- | --- | --- | --- | ---
Jun. 09, 2021 | Jun. 13, 2018 | Dec. 31, 2021 | Dec. 31, 2020 | Feb. 28, 2021
Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] |  |  |  |  |
Weighted average grant date fair value of stock options |  |  | $ 4.00 | $ 5.20 |
Aggregate intrinsic value of options exercised |  |  | $ 3,000 | $ 100,000 |
Fair value of options vested |  |  | $ 2,600,000 | 3,000,000.0 |
Number of common stock available for future grant |  |  | 3,333,791 |  |
Total stock-based compensation |  |  | $ 3,405,000 | 3,627,000 |
Employee Stock Option |  |  |  |  |
Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] |  |  |  |  |
Unrecognized employee stock based compensation expense |  |  | $ 3,900,000 |  |
Unrecognized employee stock based compensation expense, period for recognition |  |  | 2 years 5 months 26 days |  |
2018 Omnibus Incentive Plan |  |  |  |  |
Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] |  |  |  |  |
Increase in number of shares of common stock reserved for issuance | 2,500,000 |  |  |  |
Common Stock, Capital Shares Reserved for Future Issuance | 5,300,000 |  |  |  |
2018 Omnibus Incentive Plan | Performance Based Stock Option Grants |  |  |  |  |
Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] |  |  |  |  |
Issuance of option grants to purchase common stock shares |  |  |  |  | 647,000
2018 Employee Stock Purchase Plan |  |  |  |  |
Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] |  |  |  |  |
Maximum employee subscription rate |  | 15.00% |  |  |
Number of common stock available for future grant |  |  | 235,469 |  |
Number of common stock authorized for issuance |  |  | 359,545 |  |
Number of common stock stock issued |  |  | 64,975 |  |
Proceeds from Issuance |  |  | $ 300,000 |  |
Total stock-based compensation |  |  | $ 100,000 | $ 100,000 |
2018 Employee Stock Purchase Plan | Maximum |  |  |  |  |
Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] |  |  |  |  |
Percentage of fair market value of common stock |  | 85.00% |  |  |

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- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=122041274&loc=d3e301413-122809 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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- Definition The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585 + Details
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- Definition The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The increase or decrease in number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding, including vested options. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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