Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounts receivable, allowance for doubtful accounts	$ 1,913	$ 2,171
Property and equipment, accumulated depreciation	$ 3,020	$ 2,349
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	9,000,000	9,000,000
Common stock, shares issued (in shares)	6,472,038	6,472,038
Treasury stock, shares (in shares)	1,203,491	1,090,370