Consolidated Balance Sheets (unaudited) (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Common stock, par value (in dollars per share)	$ 2.50	$ 2.50
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	12,468,013	12,465,296
Common stock, shares outstanding	12,366,360	12,358,562
Preferred Stock, Par or Stated Value Per Share	$ 1	$ 1
Preferred Stock, Shares Authorized	250,000	250,000
Employee Stock Ownership Plan (ESOP), Number of Suspense Shares	101,653	106,734