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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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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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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. 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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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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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 remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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Number of options vested.

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

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Stockholders' Equity - Inducement Plan - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
OUTSTANDING OPTIONS
Outstanding at beginning of period	100,600
Outstanding at end of period			100,600
WEIGHTED-AVERAGE EXERCISE PRICE
Outstanding at beginning of period	$ 3.09
Outstanding at end of period			$ 3.09
ADDITIONAL DISCLOSURES
Weighted-average contractual term (years) exercisable	9 years		9 years 6 months
Outstanding options exercisable at end of period	1,500
Aggregate intrinsic value (in thousands) exercisable at end of period	$ 1
Inducement Plan
OUTSTANDING OPTIONS
Options exercised	0
Outstanding at end of period	100,600
WEIGHTED-AVERAGE EXERCISE PRICE
Outstanding at end of period	$ 3.09
VESTED AND EXPECTED TO VEST
Outstanding options	100,600
Weighted-Average Exercise Price	$ 3.09
Aggregate Intrinsic Value (in thousands)	$ 39
Shares vested	0	0
Options exercised	0
ADDITIONAL DISCLOSURES
Weighted-average contractual term (years) exercisable	9 years 2 months 12 days
Weighted-average contractual term outstanding	9 years 2 months 12 days
Aggregate intrinsic value (in thousands) exercisable at end of period	$ 39
Fair value of shares vested	$ 2,205