Consolidated Condensed Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Jul. 01, 2018	Dec. 31, 2017
Common Stock [Member]
Common stock, par value	$ 1.00	$ 1.00
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	10,203,821	10,203,821
Treasury stock, shares	3,062,374	3,062,374
Class B Common Stock [Member]
Common stock, par value	$ 1.00	$ 1.00
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	2,841,132	2,820,836
Treasury stock, shares	628,114	628,114