Fair value of common stock per share.

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- Definition

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

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- Definition

Aggregate number of common shares reserved for future issuance.

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- Definition

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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- Definition

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

+ References

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- Definition

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

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- Definition

Number, after shares used to satisfy grantee's tax withholding obligation for award under share-based payment arrangement, of restricted shares issued. Excludes cash used to satisfy grantee's tax withholding obligation.

+ References

No definition available.

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- Definition

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.

+ References

No definition available.

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- Definition

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

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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.

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- Definition

Number of shares issued under share-based payment arrangement.

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- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

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Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2019	Sep. 27, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved for future issuance	28,418,977		28,418,977
Fair value of common stock per share	$ 16		$ 16
Weighted-average fair value of options granted	$ 5.59	$ 0.04	$ 4.15	$ 0.04
Gross unrecognized stock-based compensation expense	$ 10,800		$ 10,800
Unrecognized stock-based compensation expense weighted average amortized period			2 years 10 months 2 days
Number of restricted common stock shares issued					994,650
Stock-based compensation expense	$ 307	$ 12	$ 3,329	$ 29
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved for future issuance	554,724		554,724
Unrecognized stock-based compensation expense weighted average amortized period			1 year 8 months 12 days
Common stock public offering price per share					$ 0.01
Stock-based compensation expense	$ 5	$ 6	$ 17	$ 17
Gross unrecognized stock-based compensation expense	$ 30		$ 30
2021 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved for future issuance						3,852,807
2019 Equity Incentive Plan \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved for future issuance	4,042,408		4,042,408
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares authorized for issuance	424,595		424,595
Number of shares issued			0
2021 Employee Stock Purchase Plan \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares reserved for future issuance	424,595		424,595