Share-Based Compensation - Options (Details) - Class A common shares - Stock options - $ / shares	6 Months Ended
Jun. 30, 2020
Number of Shares
Outstanding, beginning of the period	8,491,734
Granted	1,956,670
Exercised	(1,080,425)
Forfeited	(684,599)
Outstanding, end of the period	8,683,380
Options exercisable	3,068,290
Options unvested	5,615,090
Weighted Average Grant Date Fair Value
Outstanding, beginning of the period	$ 7.68
Granted	11.66
Exercised	3.01
Forfeited	11.30
Outstanding, end of the period	8.88
Options exercisable	8.56
Options unvested	$ 10.02

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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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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 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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Number of non-vested options outstanding.

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Weighted average grant-date fair value of non-vested options outstanding.

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

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