Note 1 - Nature of Business and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2013

Accounting Policies [Abstract]

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

	2013			2012		2011
Dividend yield	.44%	to	.53%		.86%	.88%	to	1.00%
Expected volatility	29.50%	to	30.56%		29.36%	29.64%	to	30.30%
Risk-free interest rate	1.71%	to	2.90%		1.98%	1.90%	to	3.58%
Expected life of option grants (years)		6			6		6
Weighted-average grant date fair value		$5.14			$2.79		$2.74

	2013			2012			2011
Dividend yield	.53%	to	.61%	.61%	to	.88%	.88%	to	1.12%
Expected volatility	23.05%	to	24.25%	27.20%	to	31.11%	51.62%	to	53.58%
Risk-free interest rate	.10%	to	.18%	.03%	to	.18%	.08%	to	.23%
Expected life of purchase grants (months)	3	to	6	3	to	6	3	to	6
Weighted-average grant date fair value		$2.10			$1.71			$1.68