CONDENSED CONSOLIDATED STATEMENTS OF FINANCIAL POSITION (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 27, 2014	Dec. 31, 2013	Sep. 28, 2013
Trade accounts receivable, allowances	$ 3,391	$ 2,042	$ 3,446
Treasury stock, shares	78,000	76,000	76,000
Common Stock
Common stock, par value (in dollars per share)	$ 0.6944	$ 0.6944	$ 0.6944
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0.6944	$ 0.6944	$ 0.6944
Common stock, shares issued		22,256,000	22,259,000