CONSOLIDATED STATEMENTS OF CONDITION (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Investment securities:
Held to maturity, fair value	$ 19,259	$ 63,272
STOCKHOLDERS' EQUITY
Common stock, par value (in dollars per share)	$ 2.50	$ 2.50
Common stock, shares authorized (in shares)	15,000,000	15,000,000
Common stock, shares, issued (in shares)	14,102,617	13,966,292
Common stock, shares outstanding (in shares)	11,936,879	11,800,554
Treasury stock, shares (in shares)	2,165,738	2,165,738