Net Loss Per Share Attributable to Common Stockholders - Schedule of Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net loss	$ (55,270)	$ (33,382)	$ (16,858)
Accretion of redeemable convertible preferred stock	(96)	(162)	(143)
Net loss attributable to common stockholders	$ (55,366)	$ (33,544)	$ (17,001)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	50,930	16,573	14,442
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (1.09)	$ (2.02)	$ (1.18)

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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Amount of decrease to net income for accretion of temporary equity to its redemption value to derive net income apportioned to common stockholders.

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Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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