Note 2 - Summary of Significant Accounting Policies - Weighted Average Common Shares (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Weighted average common shares outstanding - basic (in shares)	10,288,325	10,295,447	10,276,682	10,327,095
Potentially dilutive securities:
Unvested shares of restricted stock and stock options (in shares)	62,684	23,268	50,398	17,652
Weighted average common shares and common share equivalents outstanding - diluted (in shares)	10,351,009	10,318,715	10,327,080	10,344,747
Average number of potentially dilutive securities excluded from calculation (in shares)	96,000	19,800	79,753	18,277