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

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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 cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Amount of cost to be recognized for option under share-based payment arrangement.

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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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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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Net number of share options (or share units) granted during the period.

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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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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Percentage of vesting of award under share-based payment arrangement.

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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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Weighted average grant-date fair value of options vested.

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Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands						1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 01, 2021	Sep. 17, 2020	Jul. 14, 2020	Jan. 01, 2020	Jan. 01, 2019	May 07, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant								1,739,621	653,136	818,002	38,055
Weighted average exercise price								$ 2.18	$ 2.12	$ 1.92
Expense related to options granted							$ 600	$ 5,263	$ 1,175	$ 2,479
Agreement terminated								2021-02
Option granted			22,574
Option vested percentage			75.00%
Weighted average exercise price								$ 15.14	$ 5.39	$ 2.26
Aggregate intrinsic value of options exercised								$ 2,500	$ 100	$ 400
Unrecognized stock-based compensation expense								0
Options Issued and Outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total fair value of options vested								$ 2,400	$ 900	$ 1,800
Weighted-average grant date fair value of options granted								$ 9.96	$ 2.98	$ 3.95
Unrecognized compensation expense								$ 21,600
Unrecognized compensation expense, estimated weighted-average period for recognition								3 years 7 months 6 days
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total fair value of options vested								$ 0	$ 100	$ 600
Forecast
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expense related to options granted						$ 100
2018 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of additional shares added on outstanding shares	4.00%							4.00%
2018 Stock Incentive Plan \| Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares reserved for issuance	787,089
2017 and 2018 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant								1,456,492
Number of shares reserved for issuance								1,317,892
Weighted average exercise price								$ 15.62
2014 Stock Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance								69,014
Weighted average exercise price								$ 1.27
2015 Stock Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance								1,957,536
Weighted average exercise price								$ 7.43
2014 and 2015 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant								283,129
2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of additional shares added on outstanding shares										1.00%
Number of additional shares reserved for issuance				131,432	79,369
Number of shares reserved for issuance								39,290
Number of shares available for sale under employee stock purchase plan								0
2018 Employee Stock Purchase Plan \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares reserved for issuance								77,703
2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance								362,503
Weighted average exercise price								$ 14.33
Merger
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expense related to options granted								$ 100
Option granted		16,931
Weighted average exercise price		$ 16.11
Merger \| Share-based Payment Arrangement, Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting rights								one-third of the shares vesting on the first anniversary
Merger \| Share-based Payment Arrangement, Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting rights								one-third of the shares vesting in 12 equal monthly installments following such first anniversary
Merger \| Share-based Payment Arrangement, Tranche Three
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting rights								one-third of the shares vesting in accordance with the terms of his Transition Agreement which consisted of 12 months’ of accelerated vesting of his unvested options to purchase the Company’s common stock upon completion of the Merger.