CONSOLIDATED STATEMENTS OF CONDITION (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Statement of Financial Position [Abstract]
Securities held to maturity, fair value	$ 24,772	$ 26,911	$ 39,145
Allowance for loan losses	$ 14,057	$ 13,964	$ 13,143
Preferred stock, par value (in dollars per share)	$ 2.50	$ 2.50	$ 2.50
Preferred stock, shares authorized	20,000,000	20,000,000	20,000,000
Preferred stock, shares outstanding	0	0	0
Common stock, par value (in dollars per share)	$ 2.50	$ 2.50	$ 2.50
Common stock, shares authorized	20,000,000	20,000,000	20,000,000
Common stock, shares issued	7,132,459	7,108,620	7,101,368
Common stock, shares outstanding	7,069,859	7,046,020	7,038,768
Treasury stock, shares	62,600	62,600	62,600