Stock-Based Compensation - Summary of Stock Option (Details) - $ / shares	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Beginning balance		2,289,209
Number of Shares, Granted	0	804,975
Number of Shares, Exercised		(94,303)
Number of Shares, Cancelled		(25,334)
Number of Shares, Ending balance		2,974,547	2,289,209
Number of Shares, Exercisable		1,180,003
Weighted-Average Exercise Price, Beginning balance		$ 3.36
Weighted-Average Exercise Price, Granted		42.64
Weighted-Average Exercise Price, Exercised		1.31
Weighted-Average Exercise Price, Cancelled		15.96
Weighted-Average Exercise Price, Ending balance		13.95	$ 3.36
Weighted-Average Exercise Price, Exercisable		$ 2.90
Weighted Average Remaining Contractual Term (Years)		8 years 2 months 12 days	8 years 1 month 6 days
Weighted Average Remaining Contractual Term (Years), Exercisable		6 years 8 months 12 days

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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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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.

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

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

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

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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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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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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Number of share options (or share units) exercised during the current period.

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