Loans - Summary of Loans by Credit Quality Indicator (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 554,869	$ 551,133
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	305,473	304,382
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	15,722	26,690
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	32,126	20,599
Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	201,548	199,462
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	139,964	137,114
Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	112,315	110,731
Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	8,402	15,040
Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	18,190	10,295
Commercial [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,057	1,048
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	192,387	196,748
Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	170,352	174,045
Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	7,221	11,546
Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	13,615	9,994
Commercial Real Estate [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,199	1,163
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	177,404	174,259
Residential Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	180	183
Residential Real Estate [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	243	237
Residential Real Estate [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	176,981	173,839
Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	26,516	23,960
Construction & Land Development [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	22,626	19,423
Construction & Land Development [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	99	104
Construction & Land Development [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,791	4,433
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	18,598	19,052
Consumer [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	78	73
Consumer [Member] | Not Rated [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 18,520	$ 18,979