Consolidated Condensed Statements of Changes in Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Apr. 01, 2018	Apr. 02, 2017
Cash dividend per share	$ 0.25	$ 0.25
Class B Common Stock [Member]
Cash dividend per share	$ 0.25	$ 0.25
Class B common stock shares issued	20,296	21,020