Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
STOCKHOLDERS' EQUITY
Common stock, par value	$ 2.50	$ 2.50
Common stock, shares authorized	8,000,000	8,000,000
Common stock, shares issued	4,838,071	4,838,071
Treasury stock, shares	1,487,238	1,464,010