CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, shares authorized	100,000,000	25,413,000
Common stock, shares issued	25,413,000	25,413,000
Common stock, shares outstanding	17,418,000	18,774,000
Treasury stock, shares	7,995,000	6,639,000