Stock-Based Compensation - Additional Information (Details) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($) equityCompensationPlan $ / shares shares	Dec. 31, 2019 USD ($) $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense \| $	$ 1.1
Number of equity compensation plans \| equityCompensationPlan	2
Automatic increase in shares to be issue (in percentage)		4.00%
Weighted average grant date fair value (in USD per share) \| $ / shares	$ 0.34	$ 0.84
Options vested in period, fair value \| $	$ 0.5	$ 1.0
Options to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to options outstanding, weighted average period for expense to be recognized	2 years
Stock options \| 2014 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)	0.8
Options outstanding (in shares)	0.4
Stock options \| 2019 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)	4.2
Options outstanding (in shares)	3.8

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Automatic Increase In Shares To Be Issue, Percentage

+ References

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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.

+ References

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- Definition

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

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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.

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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

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

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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.

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