Note 5 - Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

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 June 30, 2018		227,500	$	2.47		5.1	$	1,411,515
Vested and exercisable at June 30, 2018		186,500	$	1.90		4.3	$	1,262,185