Note 6 - Share-based Compensation (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2019			2018
Expected dividend yield at date of grant		2.85	%		2.65	%
Expected stock price volatility		34.05	%		32.24	%
Risk-free interest rate		2.48	%		2.39	%
Expected life of options (in years)		8			8

Share-based Payment Arrangement, Activity [Table Text Block]

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Terms (Years)		Aggregate Intrinsic Value (In thousands)
Outstanding at December 31, 2018		1,373,209		$	15.99
Granted		73,331		$	38.30
Exercised		(86,247	)	$	7.34			$	2,717
Forfeited		--		$	--
Outstanding at March 31, 2019		1,360,293		$	17.74		5.22	$	28,379
Exercisable at March 31, 2019		907,432		$	14.44		3.91	$	21,928

Schedule of Nonvested Share Activity [Table Text Block]

	Common Shares Outstanding		Weighted Average Grant Date Fair Value Per Share
Outstanding at December 31, 2018		78,171	$	15.61
Granted		6,005		38.30
Vested		--		--
Forfeited		--	$	--
Outstanding at March 31, 2019		84,176	$	17.23