Stock-based Compensation - Summary of Stock Option Activity (Details) - Stock options $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares
Stock option activity
Outstanding \| shares	3,955,887
Granted \| shares	701,249
Exercised \| shares	(587,135)
Cancelled \| shares	(98,551)
Outstanding \| shares	3,971,450	3,955,887
Exercisable at end of period \| shares	2,123,646
Weighted average exercise price per share
Outstanding \| $ / shares	$ 16.00
Granted \| $ / shares	21.39
Exercised \| $ / shares	10.36
Cancelled \| $ / shares	20.69
Outstanding \| $ / shares	17.67	$ 16.00
Exercisable at end of period \| $ / shares	$ 16.95
Stock option activity, additional information
Outstanding Weighted-Average Remaining Contractual Term	7 years 8 months 12 days	7 years 6 months
Outstanding Aggregate Intrinsic Value \| $	$ 7,866	$ 21,257
Exercisable at end of period, Weighted-Average Remaining Contractual Term	6 years 8 months 12 days
Exercisable at end of period, Aggregate Intrinsic Value \| $	$ 5,058

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

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

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