Note 3 - Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

Notes Tables

Share-based Compensation, Stock Options, Activity [Table Text Block]

				Weighted-
				average
				Exercise Price
	Shares			Per Share
Outstanding, January 1, 2018		19,750		$	20.94
Exercised		(1,500	)		23.00
Outstanding, March 31, 2018		18,250		$	20.78
Exercisable, March 31, 2018		18,250		$	20.78

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

			Weighted-
			average
			Grant Date Fair
	Shares		Value Per Share
Nonvested at January 1, 2018		14,601	$	35.14
Granted		-		-
Forfeited		-		-
Nonvested at March 31, 2018		14,601	$	35.14
Expected to vest at March 31, 2018		14,601	$	35.14