Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Accounts receivable, allowance for doubtful accounts	$ 1,930,000	$ 1,276,000
Finished goods	54,904,000	57,887,000
Work in process	690,000	853,000
Raw materials	$ 10,366,000	$ 10,500,000
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	300,000	300,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	14,859,231	14,513,207
Common stock, shares outstanding (in shares)	14,859,231	14,513,207