Note 4 - Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 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 March 31, 2018		243,500	$	2.17		4.7	$	716,655
Vested and exercisable at March 31, 2018		206,500	$	1.87		4.0	$	669,565