Stockholders' Equity - Summary of stock options (Details) - $ / shares	12 Months Ended
Feb. 28, 2019	Feb. 28, 2018
Shares
Outstanding at beginning of period (in shares)	912,100	839,600
Exercisable at beginning of period (in shares)	425,400	395,405
Granted (in shares)	55,000	130,000
Exercised (in shares)	(371,100)	(57,500)
Cancelled (in shares)	(8,000)
Outstanding at end of period (in shares)	588,000	912,100
Exercisable at end of period (in shares)	171,000	425,400
Weighted Average Exercise Price
Outstanding at beginning of period (in dollars per share)	$ 0.96	$ 0.91
Granted (in dollars per share)	2.66	1.12
Exercised (in dollars per share)	(0.96)	(0.84)
Cancelled (in dollars per share)	(1.12)
Outstanding at end of period (in dollars per share)	1.10	0.96
Exercisable at beginning of period (in dollars per share)	0.92	0.89
Exercisable at end of period (in dollars per share)	0.85	0.92
Fair value vested at beginning of period (in dollars per share)	0.35	0.32
Fair value vested at end of period (in dollars per share)	$ 0.34	$ 0.35

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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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, 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 or that expired.

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Weighted average price of options that were either forfeited or expired.

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

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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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