Note 6 - Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2021

Notes Tables

Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable [Table Text Block]

	# of Shares		Wgt Avg Exercise Price		Wgt Avg Remaining Contractual Life in Years		Aggregate Intrinsic Value
Outstanding at March 31, 2021		59,000	$	17.35		7.4	$	1,389,970
Vested and exercisable at March 31, 2021		45,000	$	14.83		7.2	$	1,173,570