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		$ 7,804	$ 6,528	$ 5,701
Other comprehensive (loss) income:
Unrealized (losses) gains arising during the period on available-for-sale securities, net of income taxes of ($1,954), $80, and $1,280, respectively		(3,794)	154	2,482
Reclassification adjustment for net gain on sales of available-for-sale securities included in net income, net of income taxes of ($356), ($110), and ($57), respectively (a)	[1]	(690)	(215)	(111)
Change in defined benefit plans, net of income taxes of ($93), $185, and $7, respectively (b)	[2]	(181)	360	14
Total other comprehensive (loss) income		(4,665)	299	2,385
Total comprehensive income		$ 3,139	$ 6,827	$ 8,086

[1] Amounts are included in net gain on sales of investment securities on the Consolidated Statements of Income as a separate component within total noninterest income

[2] Amounts are included in the computation of net periodic benefit cost and are included in salaries and employee benefits on the Consolidated Statements of Income as a separate element within total noninterest expense