Note 9 - Share-based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Notes Tables

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

	Years Ended December 31,
	2015			2014			2013
Total cost of share-based compensation	$	668		$	591		$	512
Amount of income tax benefit recognized in earnings		(39	)		(104	)		(100	)
Amount charged against net income	$	629		$	487		$	412

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

	2015			2014			2013
Dividend yield		2.8	%		3.4	%		2.7	%
Expected volatility		32	%		37	%		42	%
Risk-free interest rate		1.6	%		1.7	%		1.0	%
Expected lives (in years)		6.8			6.4			5.6

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

						Weighted
				Weighted		Average		Aggregate
				Average		Remaining		Intrinsic
				Exercise		Contractual		Value
	Shares			Price		Term		(in thousands)
Options outstanding, December 31, 2012		838,662		$	11.84		3.9	$	2,346
Granted		10,000			14.16
Exercised		(206,675	)		10.23
Cancelled or expired		(19,687	)		14.12
Options outstanding, December 31, 2013		622,300			12.34		3.7		2,175
Granted		298,500			16.60
Exercised		(175,800	)		10.97
Cancelled or expired		(22,325	)		15.04
Options outstanding, December 31, 2014		722,675			14.35		4.6		2,555
Granted		206,300			14.30
Exercised		(115,922	)		10.24
Cancelled or expired		(15,675	)		15.51
Options outstanding, December 31, 2015		797,378		$	14.91		4.7	$	453
Options exercisable, December 31, 2015		507,978		$	14.90		3.6	$	380

Schedule of Share-based Compensation Stock Options Unvested Activity [Table Text Block]

				Weighted
				Average
	Number of			Grant Date
	Shares			Fair Value
Unvested at December 31, 2014		227,400		$	4.35
Options granted		206,300			3.40
Options cancelled		(12,825	)		3.71
Options vested		(131,475	)		4.79
Unvested at December 31, 2015		289,400		$	3.48