Stock-based Compensation - Schedule Options to Purchase Common Stock (Details) - 2019 Plan - USD ($)	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Number of Shares
Number of shares, options outstanding, beginning balance (in shares)	731,189
Granted (in shares)	4,064,950
Cancelled (in shares)	(527,862)
Number of shares, options outstanding, ending balance (in shares)	4,268,277	731,189
Options exercisable (in shares)	450,405
Weighted Average Exercise Price
Beginning balance, weighted average exercise price (in USD per share)	$ 4.59
Weighted average exercise price, granted (in USD per share)	0.41
Weighted average exercise price, cancelled (in USD per share)	1.96
Ending balance, weighted average exercise price (in USD per share)	0.94	$ 4.59
Weighted average exercise price, options exercisable (in USD per share)	$ 4.34
Additional Disclosures
Beginning balance, weighted average remaining contractual life	9 years 1 month 6 days	8 years
Weighted average remaining contractual life, options exercisable	6 years 7 months 6 days
Aggregate intrinsic value, beginning balance	$ 24,028
Aggregate intrinsic value, ending balance	7,072	$ 24,028
Aggregate intrinsic value, options exercisable	$ 450

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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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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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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