Note 2 - Summary of Significant Accounting Policies - Reconciliation of Net Income and Number of Shares Used in Computations of Basic and Diluted EPS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 3,168,000	$ 1,041,000
Shares (denominator):
Basic weighted average common shares outstanding (in shares)	16,835,129	18,197,109
Add: Dilutive effect of common stock options (in shares)		41,255
Diluted weighted average common shares outstanding (in shares)	16,835,129	18,238,364
Earnings per common share:
Basic earnings per common share (in dollars per share)	$ 0.19	$ 0.06
Diluted earnings per common share (in dollars per share)	$ 0.19	$ 0.06