Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Trade receivables, allowance for doubtful accounts	$ 304	$ 346
Common stock par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	33,528,915	32,836,930
Treasury stock, at cost (in shares)	1,729,727	1,738,624