CONSOLIDATED BALANCE SHEET (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.125	$ 0.125
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	115,858,190	115,858,190
Common stock, shares outstanding	78,947,381	79,213,037
Treasury stock, shares at cost	36,910,809	36,645,153