Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accounts receivable, allowance	$ 200	$ 299
Preferred stock, par value (in dollars per share)	$ 0.00015	$ 0.00015
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.00015	$ 0.00015
Common stock, shares authorized (in shares)	70,000,000	70,000,000
Common stock, shares issued (in shares)	37,880,000	37,476,000
Common stock, shares outstanding (in shares)	31,311,000	31,111,000
Treasury stock, shares (in shares)	6,569,000	6,365,000