Foreclosed Assets - Summary of Expenses Applicable to Foreclosed Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Other Real Estate And Foreclosed Assets [Abstract]
Net gain on sales of foreclosed assets	$ (133)	$ (58)
Write-down of foreclosed property	180	175
Operating expenses, net of rental income	30	50
Total	$ 77	$ 167