Note 8. Stock Options and Restricted Stock Units (Details) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Number of options outstanding, beginning	127,563	98,563
Number of options granted	0	31,500
Number of options exercised	(36,250)	0
Number of options forfeited/cancelled	(16,083)	(2,500)
Number of options outstanding, ending	75,230	127,563
Range of exercise price options outstanding, beginning	$6.80 - $17.40	$6.80 - $17.40
Range of exercise price options granted	$0.00	$10.75 - $13.21
Range of exercise price options exercised	$7.76 - $17.40	$0.00
Range of exercise price options forfeited/cancelled	$9.26 - $17.40	$13.21
Range of exercise price options outstanding, ending	$6.80 - $17.40	$6.80 - $17.40
Weighted average exercise price outstanding, beginning	$ 12.63	$ 12.56
Weighted average exercise price granted	.00	12.90
Weighted average exercise price exercised	12.47	.00
Weighted average exercise price forfeited/cancelled	15.17	13.21
Weighted average exercise price outstanding, ending	$ 12.16	$ 12.63
Aggregate intrinsic value outstanding, beginning	$ 142,818	$ 127,306
Aggregate intrinsic value granted	$ 0	$ 0
Aggregate intrinsic value exercised	$ 295,921	$ 0
Aggregate intrinsic value forfeited/cancelled	$ 22,682	$ 0
Aggregate intrinsic value outstanding, ending	$ 402,275	$ 142,818

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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

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The combined weighted average of the accumulated differences between the fair values on underlying shares and exercises prices to acquire such shares as of the grant date on options that were either forfeited or lapsed.

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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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The grant-date intrinsic value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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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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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 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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