Note 14 - Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

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

	201 8			2017			2016
Expected option life in years (1)		6.0			6.0			6.0
Expected stock price volatility percentage (2)		26	%		25	%		25	%
Risk-free interest rate percentage (3)		2.8	%		2.0	%		1.4	%
Expected dividend yield (4)		0.48	%		0.59	%		0.50	%
Fair value as of the date of grant	$	6.19		$	4.34		$	3.17

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

	Shares			Weighted Average Exercise Price
Outstanding at December 31, 2017		918,583		$	12.02
Granted		154,500			21.26
Exercised		(105,588	)		8.91
Forfeited		(28,302	)		15.66
Outstanding at December 31, 2018		939,193		$	13.78
Exercisable at December 31, 2018		545,713		$	11.49

Schedule of Nonvested Share Activity [Table Text Block]

	Shares			Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life (in Years)
Nonvested at December 31, 2017		413,228		$	3.79		5.1
Granted		154,500			6.19		6.7
Vested		(146,546	)		3.73		3.4
Forfeited		(27,702	)		4.26		5.1
Nonvested at December 31, 2018		393,480		$	4.72		5.2

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

	Shares				Weighted Average Grant Date Fair Value
Nonvested at December 31, 2017		322,662			$	13.32
Granted		77,700				20.31
Vested		(182,481	)	(1)		14.55
Forfeited		(31,973	)			13.81
Nonvested at December 31, 2018		185,909			$	14.89