Share-based Compensation - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Number of Options Outstanding
Balance outstanding (in shares)	1,837,576
Granted (in shares)	367,265
Exercised (in shares)	(62,457)
Forfeited/canceled (in shares)	(97,750)
Balance outstanding (in shares)	2,044,634
Weighted average fair value (in dollars per share)	$ 10.64
Weighted-Average Exercise Price
Options outstanding (in dollars per share)	14.54
Granted (in dollars per share)	19.11
Exercised (in dollars per share)	5.99
Forfeited/canceled (in dollars per share)	15.70
Options outstanding (in dollars per share)	$ 15.57
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-average remaining contractual term	8 years 14 days	8 years 21 days
Aggregate intrinsic value	$ 10,046		$ 24,122

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Weighted average price of options that were either forfeited or expired.

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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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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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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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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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