Maximum authorized payroll deduction percentage of eligible compensation for eligible employees.

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- Definition

Payments for relinquishment of right to purchase common stock upon exercise of stock options.

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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

The cash outflow to reacquire common stock during the period.

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- Definition

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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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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No definition available.

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

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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.

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- Definition

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

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No definition available.

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- Definition

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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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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Stock-based Compensation - Additional Information (Details) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Oct. 01, 2020	Mar. 03, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 03, 2020	Apr. 30, 2019	Dec. 28, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense			$ 436	$ 627	$ 713	$ 913
Payments for repurchase of common stock		$ 100			$ 210	$ 40
Payments for relinquishment of right to purchase common stock upon exercise of stock options		$ 800
2015 Incentive Stock Option and Grant Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, common stock shares reserved for issuance							5,058,203	3,614,753	2,525,327
Common stock, shares remained available for future grant			2,364,975		2,364,975
Awards granted					1,467,424
Stock-based compensation, options vesting description					Options generally vest over a period of five or eight years, with a cliff vesting at one year and quarterly vesting thereafter and options that lapse or are forfeited are available to be granted again.
Contractual life of options from the date of grant					10 years
2015 Incentive Stock Option and Grant Plan \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, options vesting period					5 years
2015 Incentive Stock Option and Grant Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, options vesting period					8 years
2015 Incentive Stock Option and Grant Plan \| Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards granted	0
2020 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, common stock shares reserved for issuance			6,567,144		6,567,144
Awards granted					0
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, common stock shares reserved for issuance			437,809		437,809
Maximum authorized payroll deduction percentage of eligible compensation for eligible employees					15.00%
Shares issued under employee stock purchase plan					0