Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares as percentage of common shares outstanding	5.00%
Award vesting period	4 years
Number of shares reserved for future issuance (in shares)	12,448,841
Accrued and other liabilities, related to shares held by employees and directors that were subject to repurchase	$ 2.8	$ 5.3
Other long term liabilities, related to shares held by employees and directors that were subject to repurchase	$ 3.2	$ 6.1
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Stock options to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (in dollars per share)	$ 18.41
Unrecognized stock based compensation expense	$ 98.2
Unrecognized stock based compensation expense, weighted average recognition period	3 years 45 days
Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock based compensation expense	$ 55.3
Unrecognized stock based compensation expense, weighted average recognition period	3 years 133 days
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option grant period	10 years
Option exercise price as percentage of fair value of common stock on grate date	100.00%

Number of shares as percentage of common shares outstanding.

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Option exercise price as percentage of fair value of common stock on grate date.

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Stock option granted period.

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Aggregate number of common shares reserved for future issuance.

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- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for stock option plans and other equity-based compensation arrangements payable within one year (or the operating cycle, if longer).

+ References

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Aggregate carrying value as of the balance sheet date of the liabilities for stock option plans and other equity-based compensation arrangements payable after one year (or the operating cycle, if longer).

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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 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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