Other Non-Interest Expenses - Schedule of Company's Total Interest and Non-Interest Income Included in Other Non-Interest Expenses (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Other Income And Expenses [Abstract]
Software amortization and maintenance		$ 445	$ 358
Debit card expense		310	326
Directors fees	[1]	251	267
Internet and data charges	[1]	197	181
Supplemental retirement plans	[1]	$ 195	$ 187

[1] Expenses for these categories are below the 1% threshold but are presented herein for comparative purposes.