Loans - Summary of Loan Credit Quality (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 179,663	$ 154,027
Mortgage Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	140,932	120,395
Mortgage Receivable [Member] | Commercial Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	56,472	52,661
Mortgage Receivable [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	66,835	51,858
Mortgage Receivable [Member] | Construction Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	17,625	15,876
Loans and Finance Receivables [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	35,883	30,755
Loans and Finance Receivables [Member] | Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,848	2,877
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	169,379	146,532
Pass [Member] | Mortgage Receivable [Member] | Commercial Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	51,721	50,654
Pass [Member] | Mortgage Receivable [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	62,384	47,357
Pass [Member] | Mortgage Receivable [Member] | Construction Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	17,312	15,714
Pass [Member] | Loans and Finance Receivables [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	35,155	30,006
Pass [Member] | Loans and Finance Receivables [Member] | Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,807	2,801
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	4,655	3,807
Special Mention [Member] | Mortgage Receivable [Member] | Commercial Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,800	0
Special Mention [Member] | Mortgage Receivable [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,228	3,065
Special Mention [Member] | Mortgage Receivable [Member] | Construction Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	87	154
Special Mention [Member] | Loans and Finance Receivables [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	508	520
Special Mention [Member] | Loans and Finance Receivables [Member] | Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	32	68
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	5,629	3,688
Substandard [Member] | Mortgage Receivable [Member] | Commercial Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,951	2,007
Substandard [Member] | Mortgage Receivable [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,223	1,436
Substandard [Member] | Mortgage Receivable [Member] | Construction Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	226	8
Substandard [Member] | Loans and Finance Receivables [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	220	229
Substandard [Member] | Loans and Finance Receivables [Member] | Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	9	8
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Doubtful [Member] | Mortgage Receivable [Member] | Commercial Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Doubtful [Member] | Mortgage Receivable [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Doubtful [Member] | Mortgage Receivable [Member] | Construction Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Doubtful [Member] | Loans and Finance Receivables [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Doubtful [Member] | Loans and Finance Receivables [Member] | Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Loss [Member] | Mortgage Receivable [Member] | Commercial Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Loss [Member] | Mortgage Receivable [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Loss [Member] | Mortgage Receivable [Member] | Construction Real Estate Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Loss [Member] | Loans and Finance Receivables [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Loss [Member] | Loans and Finance Receivables [Member] | Consumer and Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 0	$ 0