Other Real Estate Owned and Other Repossessed Assets - Expenses Related to Foreclosed and Repossessed Assets (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other Real Estate And Foreclosed Assets [Abstract]
Net (gain) loss on sales	$ 90,000	$ 12,000
Provision for unrealized losses (gains), net	(38,000)	1,000
Operating expenses, net of rental income	62,000	72,000
Total expenses	$ 114,000	$ 85,000