Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
STOCKHOLDERS' EQUITY
Common stock, par value	$ 2.50	$ 2.50
Common stock, shares authorized	8,000,000	8,000,000
Common stock, shares issued	4,788,965	4,751,060
Treasury stock, shares	1,464,010	1,402,517