Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Apr. 02, 2017	Dec. 31, 2016
Trade accounts receivable, allowance for doubtful account	$ 276	$ 277
Preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	40,000,000	40,000,000
Common stock, shares issued (in shares)	19,505,057	19,324,723
Common stock, shares outstanding (in shares)	15,489,305	15,308,971
Treasury stock, shares (in shares)	4,015,752	4,015,752