STOCKHOLDERS' EQUITY - Intrinsic value (Details)	9 Months Ended
Sep. 30, 2020 USD ($) $ / shares shares
Options Outstanding
Aggregate Intrinsic Value \| $	$ 6,279,000
Options Exercisable
Number Exercisable at September 30, 2020 \| shares	3,180,106
Weighted Average Exercise Price	$ 6.15
Aggregate Intrinsic Value \| $	$ 6,104,740
$2.65 - $14.50
Options Outstanding
Range of Exercise Price, Lower Range Limit	$ 2.65
Range of Exercise Price, Upper Range Limit	$ 14.50
Number Outstanding at September 30, 2020 \| shares	5,234,948
Weighted Average Exercise Price	$ 6.36
Weighted Average Remaining Life (Years)	7 years 4 months 24 days
Aggregate Intrinsic Value \| $	$ 9,210,292

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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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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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