Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Options Outstanding
Number of Options Outstanding, Beginning (shares)	1,611,385
Number of Options, Exercised (shares)	(984,068)
Number of Options Outstanding, Ending (shares)	627,317	1,611,385
Weighted-Average Exercise Price per Share
Weighted Average Exercise Price per Share, Outstanding, Beginning (in dollars per share)	$ 8.64
Weighted-Average Exercise Price per Share, Exercised (in dollars per share)	9.13
Weighted Average Exercise Price per Share, Outstanding, Ending (in dollars per share)	$ 7.86	$ 8.64
Options outstanding, weighted-average remaining contractual term	3 years 5 months 23 days	3 years 7 months 6 days
Options outstanding, aggregate intrinsic value	$ 51,733,285	$ 47,171,160
Stock option awards (in shares)	0	0	0

Gross number of share options (or share units) granted during the period.

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- Definition

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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- Definition

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

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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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