Note 1 - Summary of Significant Accounting Policies - Weighted Average Number of Shares (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Average number of common shares outstanding (in shares)	6,957,974	6,953,849	6,948,789
Effect of dilutive options (in shares)	0	3,245	10,345
Average number of common shares outstanding used to calculate diluted earnings per common share (in shares)	6,957,974	6,957,094	6,959,134