Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Securities available for sale, amortized cost	$ 334,846	$ 283,185
Securities held to maturity, fair value	$ 85,749	$ 120,093
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	7,184,922	7,168,869
Common stock, shares outstanding	6,887,856	6,855,294
Treasury stock, shares	585,866	612,935
Deferred Compensation Arrangements
Common stock, shares outstanding	288,800	299,360
Preferred Class A non-voting
Preferred stock, shares authorized	200,000	200,000
Preferred stock, shares outstanding	0	0
Preferred Class B voting
Preferred stock, shares authorized	1,500,000	1,500,000
Preferred stock, shares outstanding	0	0