Condensed Financial Information of Parent Company - Condensed Income Statements (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Interest income	$ 17,936	$ 16,253
Interest expense	3,525	3,034
Net interest expense	14,411	13,219
Non-interest income	4,610	3,359
Non-interest expense	15,233	14,802
Income tax benefit	966	(187)
Net income	2,535	366
Parent Company
Condensed Financial Statements, Captions [Line Items]
Interest income	17	6
Interest expense	472	279
Net interest expense	(455)	(273)
Non-interest income	678	629
Non-interest expense	1,261	839
Loss before income taxes and equity in undistributed earnings of subsidiaries	(1,038)	(483)
Income tax benefit	(194)	(28)
Loss before equity in undistributed earnings of subsidiaries	(844)	(455)
Equity in undistributed earnings of subsidiaries	3,379	821
Net income	$ 2,535	$ 366