Schedule of Changes in Common Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options outstanding, beginning of year	3,611,850	4,303,900
Options granted	474,750	649,850
Options, Exercised	(383,350)	(31,276)
Options, Expired	(20,000)	(765,000)
Options, Forfeited	(167,025)	(545,624)
Options outstanding, end of year	3,516,225	3,611,850
Options exercisable at year end	2,566,100	2,157,336
Weighted Average Exercise Price, Outstanding at beginning of year	$ 0.51	$ 0.75
Weighted Average Exercise Price, Granted	1.62	0.74
Weighted Average Exercise Price, Exercised	0.46	0.45
Weighted Average Exercise Price, Expired	0.83	2.00
Weighted Average Exercise Price, Forfeited	1.15	0.61
Weighted Average Exercise Price, Outstanding at end of year	0.63	0.51
Weighted Average Exercise Price, Options exercisable at end of year	0.47	0.46
Weighted-average fair value of options granted during the year	$ 1.10	$ 0.50