Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 2,779	$ 2,345	$ 3,783	$ 4,339
Other comprehensive (loss) income:
Unrealized (losses) gains arising during the period on available-for-sale securities, net of income taxes impact, respectively		(333)	1,480	(2,156)	1,859
Reclassification adjustment for net gain on sales of available-for-sale securities included in net income, net of income taxes impact, respectively	[1]	(3)	(8)	(81)	(13)
Change in defined benefit plans, net of income taxes impact, respectively	[2]	1,043	(1)	1,042	(4)
Total other comprehensive (loss) income		707	1,471	(1,195)	1,842
Total comprehensive income		$ 3,486	$ 3,816	$ 2,588	$ 6,181

[1] Amounts are included in net gain on sales of investment securities on the Consolidated Statements of Income as a separate element 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.