Foreclosed Assets - Summary of Foreclosed Properties Activity (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	$ 2,397	$ 1,736
Foreclosure	4,268	354
Sales	(1,666)	(1,319)
Reduction in Values	(10)
Gain (Loss) on Sale	(14)	(30)
Ending Balance	4,975	741
Multi-Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	1,775
Foreclosure		141
Sales	(1,001)
Gain (Loss) on Sale	(24)
Ending Balance	750	141
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Foreclosure		15
Sales		(19)
Gain (Loss) on Sale		4
One-to-Four Family Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	135	55
Foreclosure	1,025
Sales	(147)	(43)
Gain (Loss) on Sale	12	(12)
Ending Balance	1,025
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	28
Foreclosure		68
Sales	(18)
Reduction in Values	(10)
Ending Balance		68
Land [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance		943
Foreclosure	3,200	130
Sales		(987)
Gain (Loss) on Sale		(13)
Ending Balance	3,200	73
Non-Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	459	738
Foreclosure	43
Sales	(500)	(270)
Gain (Loss) on Sale	$ (2)	(9)
Ending Balance		$ 459