Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)	Mar. 31, 2017	Dec. 31, 2016	[1]
Allowance for doubtful accounts	$ 67,000	$ 66,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares outstanding (in shares)	15,048,856	15,411,556

[1] The condensed consolidated balance sheet as of December 31, 2016 has been prepared using information from the audited consolidated balance sheet as of that date.