Note 4 - Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2018

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three months ended
	March 31,
	2018		2017
Net income	$	10,549,961	$	9,184,965
Basic EPS	$	0.76	$	0.70
Diluted EPS	$	0.74	$	0.68
Weighted average common shares outstanding		13,888,661		13,133,382
Weighted average common shares issuable upon exercise of stock options and under the employee stock purchase plan		316,923		355,035
Weighted average common and common equivalent shares outstanding		14,205,584		13,488,417