Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 4,871	$ 4,378	$ 3,869
Securities available for sale:
Unrealized holding (losses) gains on available-for-sale securities	(3,719)	(692)	5,465
Tax effect	1,265	235	(1,858)
Reclassification adjustment for net gains realized in net income	(466)	(75)	(588)
Tax effect	158	26	200
Total securities available-for-sale	(2,762)	(506)	3,219
Change in post-retirement obligations	39	(108)	45
Total other comprehensive (loss) income	(2,723)	(614)	3,264
Total comprehensive income	$ 2,148	$ 3,764	$ 7,133