Significant Accounting Policies - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Significant Accounting Policies [Line Items]
Personal loans charged off period no later than period	180 days
Percentage of excess loan balance for watch category	90.00%
Impaired loans measurement	Impaired loans measured for impairment generally include (1) all loans risk rated Special Mention or worse with balances of $400 thousand or more or where the borrower has filed for bankruptcy; and (2) all loans classified as a TDR .
Loan Receivables	$ 405,682,000	$ 161,033,000
Number of ESOP unit	2
Amortize of ESOP	9 years
Special Mention
Significant Accounting Policies [Line Items]
Loan Receivables	$ 833,000	$ 2,030,000
Residential First Mortgages
Significant Accounting Policies [Line Items]
Minimum balance in order to assign a risk rating grade	1,000,000
Consumer and Other Loans
Significant Accounting Policies [Line Items]
Minimum balance in order to assign a risk rating grade	$ 250,000
Minimum
Significant Accounting Policies [Line Items]
Number of days past due for a loan to remain on accrual status	90 days
Minimum | Special Mention
Significant Accounting Policies [Line Items]
Loan Receivables	$ 400,000