CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value (USD per share)	$ 1	$ 1
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	24,071,683	23,783,440
Common stock, shares outstanding	23,719,522	23,431,279
Treasury stock, common shares	352,161	352,161