Note 2 - Summary of Significant Accounting Policies - Weighted Average Common Shares (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Weighted average common shares outstanding - basic (in shares)	10,355,673	10,288,325	10,341,552	10,276,682
Potentially dilutive securities:
Unvested shares of restricted stock and stock options (in shares)		62,684	35,953	50,398
Weighted average common shares and common share equivalents outstanding - diluted (in shares)	10,355,673	10,351,009	10,377,505	10,327,080
Average number of potentially dilutive securities excluded from calculation (in shares)	360,970	96,000	188,339	79,753