Note 13 - Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2015

Notes Tables

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

	20 15			2014			2013
Expected option life in years (1)		6.0			6.0			6.1
Expected stock price volatility percentage (2)		25	%		27	%		33	%
Risk-free interest rate percentage (3)		1.8	%		1.9	%		1.5	%
Expected dividend yield (4)		0.44	%		0.46	%		0.51	%
Fair value as of the date of grant	$	5.96		$	6.25		$	5.46

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

	Shares			Weighted Average Exercise Price
Outstanding at December 31, 2014		977,867		$	14.74
Granted		154,000			22.37
Exercised		(270,283	)		12.91
Forfeited		(11,400	)		17.70
Outstanding at December 31, 2015		850,184		$	16.67
Exercisable at December 31, 2015		512,634		$	14.50

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, 2014		282,550		$	5.60		5.3
Granted		154,000			5.96		6.4
Vested		(89,300	)		5.62		3.6
Forfeited		(9,700	)		5.40		4.7
Nonvested at December 31, 2015		337,550		$	5.77		5.4

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

	Shares			Weighted Average Grant Date Fair Value
Nonvested at December 31, 2014		150,517		$	16.37
Granted		54,500			21.80
Vested		(43,620	) (1)		16.90
Forfeited		(19,952	)		13.12
Nonvested at December 31, 2015		141,445		$	18.76