Income Taxes - Summary of Differences Between Statutory Federal Income Tax Expense (Benefit) and Actual Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	3 Months Ended						12 Months Ended
	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense Benefit Continuing Operations Income Tax Reconciliation [Abstract]
Statutory federal tax at 34%							$ 162	$ (293)
Increase (decrease) resulting from:
State taxes, net of federal tax effect							24	25
Bank-owned life insurance							(81)	(217)
Tax exempt income							(125)	(139)
Dividends received deduction							(4)	(26)
Change in valuation allowance							2	530
Other, net							35	12
Total tax expense (benefit)	$ 10	$ 3	$ (103)	$ (1)	$ (1)	$ (3)	$ 13	$ (108)