CONSOLIDATED BALANCE SHEET (UNAUDITED) (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock, shares authorized (in shares)	3,000,000	3,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 8.33	$ 8.33
Common stock, shares authorized (in shares)	15,000,000	15,000,000
Common stock, shares issued (in shares)	5,008,720	5,007,109
Common stock, shares outstanding (in shares)	4,688,570	4,734,657
Treasury stock (in shares)	320,150	272,452