Consolidated Condensed Statements of Changes in Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended	9 Months Ended
Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Cash dividend per share	$ 0.25	$ 0.25	$ 0.75	$ 0.75
Class B Common Stock [Member]
Cash dividend per share	$ 0.25	$ 0.25	$ 0.75	$ 0.75
Class B common stock shares issued			20,296	21,020

Number of new stock issued during the period.

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