CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($)	Jul. 01, 2017	Dec. 31, 2016
Current Assets
Accounts receivable, allowances	$ 480,000	$ 430,000
Shareholders' Equity
Voting Preferred Stock, par value (in dollars per share)	$ 0	$ 0
Voting Preferred Stock, shares authorized (in shares)	1,000,000	1,000,000
Nonvoting Preferred Stock, par value (in dollars per share)	$ 0	$ 0
Nonvoting Preferred Stock, shares authorized (in shares)	1,000,000	1,000,000
Common Stock, par value (in dollars per share)	$ 0	$ 0
Common Stock, shares authorized (in shares)	50,000,000	50,000,000
Common Stock, shares issued (in shares)	8,954,297	8,950,827
Common Stock, shares outstanding (in shares)	6,259,568	6,256,098
Treasury Stock, shares (in shares)	2,694,729	2,694,729