Stockholders' Equity - Stock option activity (Details) - $ / shares	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020
Shares
Granted	489,719	810,333
Stock options \| LGJV
Shares
Outstanding at December 31, 2020	43,676
Outstanding at September 30, 2021	43,676
Weighted-Average Exercise Price
Outstanding at December 31, 2020	$ 7.23
Outstanding at September 30, 2021	$ 7.23
Stock options \| Director and Employee
Shares
Outstanding at December 31, 2020	5,411,930
Granted	489,719
Exercised	585,735
Forfeited	15,000
Outstanding at September 30, 2021	5,300,914
Vested at September 30, 2021	3,366,804
Weighted-Average Exercise Price
Outstanding at December 31, 2020	$ 12.52
Granted	16.72
Exercised	8.30
Forfeited	7.00
Outstanding at September 30, 2021	13.39
Vested at September 30, 2021	$ 15.11

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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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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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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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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

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