Loans Receivable, Credit Quality for Loans and the Allowance for Loan Losses - Summary of Credit Quality Indicators and Total Credit Exposure by Internally Assigned Grades (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	$ 398,493	$ 409,845
Home Equity Lines of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	18,909	17,437
Excellent [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	347	363
Good [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	3,982	4,233
Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	363,127	369,871
Satisfactory [Member] | Home Equity Lines of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	18,185	16,671
Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	15,468	17,316
Watch [Member] | Home Equity Lines of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	335	338
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	5,636	5,704
Special Mention [Member] | Home Equity Lines of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	28	28
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	9,933	12,358
Substandard [Member] | Home Equity Lines of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	361	400
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	46,330	46,076
Commercial [Member] | Excellent [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	241	249
Commercial [Member] | Good [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	2,607	2,729
Commercial [Member] | Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	40,563	39,193
Commercial [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,046	1,206
Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	475	443
Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,398	2,256
Commercial Real Estate Non-owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	104,630	110,455
Commercial Real Estate Non-owner Occupied [Member] | Good [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	34	111
Commercial Real Estate Non-owner Occupied [Member] | Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	94,055	99,010
Commercial Real Estate Non-owner Occupied [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	5,377	5,730
Commercial Real Estate Non-owner Occupied [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	2,252	2,270
Commercial Real Estate Non-owner Occupied [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	2,912	3,334
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	76,862	69,647
Commercial Real Estate Owner Occupied [Member] | Good [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,134	1,190
Commercial Real Estate Owner Occupied [Member] | Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	69,844	60,806
Commercial Real Estate Owner Occupied [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	2,895	4,290
Commercial Real Estate Owner Occupied [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,466	1,530
Commercial Real Estate Owner Occupied [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,523	1,831
Commercial Real Estate 1-4 Family Investment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	25,229	25,398
Commercial Real Estate 1-4 Family Investment [Member] | Good [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	28	35
Commercial Real Estate 1-4 Family Investment [Member] | Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	18,123	17,990
Commercial Real Estate 1-4 Family Investment [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	5,168	5,238
Commercial Real Estate 1-4 Family Investment [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,254	1,269
Commercial Real Estate 1-4 Family Investment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	656	866
Commercial Land and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	9,166	18,599
Commercial Land and Land Development [Member] | Good [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	179	168
Commercial Land and Land Development [Member] | Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	8,738	18,070
Commercial Land and Land Development [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	249	111
Commercial Land and Land Development [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		250
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	112,514	117,669
Residential Real Estate [Member] | Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	108,872	113,681
Residential Real Estate [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	398	403
Residential Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	161	164
Residential Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	3,083	3,421
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	4,853	4,564
Consumer [Member] | Excellent [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	106	114
Consumer [Member] | Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	$ 4,747	$ 4,450