Note 10 - Stock Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

Share-based Payment Arrangement, Option, Activity [Table Text Block]

		20 20			201 9
Options outstanding at January 1				126,500				207,500
Options cancelled				-				(16,000	)
Options exercised				-				(107,000	)
Options granted				-				42,000
Options outstanding at December 31				126,500				126,500
Options available for grant at December 31				885,620				763,000
Options exercisable at December 31				102,500				84,500
Exercise price ranges per share:
Granted				N/A		$19.99	-	$39.11
Exercised				N/A		$0.69	-	$7.80
Outstanding		$1.52	-	$39.11		$1.52	-	$39.11
Weighted average exercise price per share:
Granted				-	$			25.45
Exercised				-	$			1.97
Outstanding at December 31	$			8.94	$			8.94
Exercisable at December 31	$			5.61	$			2.21

Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

Options Outstanding:
Range of Exercise Price			Number Outstanding		Wgt. Avg. Contractual Life Remaining (in years)		Wgt. Avg. Exercise Price		Aggregate Intrinsic Value
$1.52	-	$1.72		67,500		0.5	$	1.59	$	2,600,325
$3.50	-	$39.11		59,000		7.6	$	17.35	$	1,342,770
$1.52	-	$39.11		126,500		3.8	$	8.94	$	3,943,095

Options Exercisable:
Range of Exercise Price			Number Exercisable		Wgt. Avg. Contractual Life Remaining (in years)		Wgt. Avg. Exercise Price		Aggregate Intrinsic Value
$1.52	-	$1.72		67,500		0.5	$	1.59	$	2,600,325
$3.50	-	$39.11		35,000		7.3	$	13.36	$	936,370
$1.52	-	$39.11		102,500		2.8	$	5.61	$	3,536,695