Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)	Sep. 27, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Trade accounts receivable allowance for doubtful accounts	$ 361,000	$ 340,000
Preferred stock - par value (in dollars per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	18,992,380	18,941,544
Common stock, shares outstanding	15,153,573	17,340,813
Treasury stock shares	3,838,807	1,600,731