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SHARE-BASED COMPENSATION (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2021
SHARE-BASED COMPENSATION |
Summary of the Company's restricted stock unit award program | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | Weighted-Average | ​
​ |  | ​ | ​ | Grant Date | ​
​ | ​ | Units | ​ | Fair Value |
Outstanding – January 1, 2021 | ​ | 1,841,150 | ​ | $ | 22.09 | ​
Granted | ​ | 136,295 | ​ | $ | 86.96 | ​
Vested | ​ | (442,690) | ​ | $ | 17.18 | ​
Forfeited(1) | ​ | (52,356) | ​ | $ | 29.59 | ​
Outstanding – December 31, 2021 | ​ | 1,482,399 | ​ | $ | 29.25 | ​
(1) | Forfeitures are recognized as they occur.
Schedule of restricted stock units granted during the year | The Compensation Committee of the Company’s Board of Directors granted RSUs during the years ended December 31 as follows: ​ k
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | Weighted-Average |
​ | ​ | ​ | ​ | Grant Date |
​ |  | Units |  | Fair Value |
2021 |  | 136,295 | ​ | $ | 86.96 | ​
2020 |  | 579,660 | ​ | $ | 19.22 | ​
2019 |  | 386,840 | ​ | $ | 27.75 | ​

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- Definition Tabular disclosure of the weighted-average grant-date fair value of restricted stock units granted during the year. + References No definition available. + Details
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- Definition Tabular disclosure of the change in restricted stock units (RSUs). + References No definition available. + Details
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