Fair Values of Assets and Liabilities - Fair Value, by Balance Sheet Grouping (Detail) - USD ($) $ in Thousands	Mar. 31, 2022		Dec. 31, 2021
Securities available-for-sale:
Securities available-for-sale, at fair value	$ 98,490		$ 91,365
U.S. Government-sponsored enterprises obligations [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	6,087		5,971
U.S. Government agency small business administration pools guaranteed by SBA [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	7,272	[1]	5,045
Collateralized mortgage obligations issued by the FHLMC, FNMA and GNMA [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	3,947	[1]	3,332
Residential mortgage backed securities [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	23,620		23,332
Municipal bonds [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	53,642		50,613
Fair Value, Measurements, Recurring [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	3,922		3,072
Fair Value, Measurements, Recurring [Member] | U.S. Government-sponsored enterprises obligations [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	6,087		5,971
Fair Value, Measurements, Recurring [Member] | U.S. Government agency small business administration pools guaranteed by SBA [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	7,272		5,045
Fair Value, Measurements, Recurring [Member] | Collateralized mortgage obligations issued by the FHLMC, FNMA and GNMA [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	3,947		3,332
Fair Value, Measurements, Recurring [Member] | Residential mortgage backed securities [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	23,620		23,332
Fair Value, Measurements, Recurring [Member] | Municipal bonds [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	53,642		50,613
Fair Value, Measurements, Recurring [Member] | Derivative [Member]
Assets, Fair Value Disclosure
Liabilities, Fair Value Disclosure	635		200
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	3,922		3,072
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government-sponsored enterprises obligations [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	6,087		5,971
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government agency small business administration pools guaranteed by SBA [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	7,272		5,045
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Collateralized mortgage obligations issued by the FHLMC, FNMA and GNMA [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	3,947		3,332
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential mortgage backed securities [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	23,620		23,332
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal bonds [Member]
Securities available-for-sale:
Securities available-for-sale, at fair value	53,642		50,613
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative [Member]
Assets, Fair Value Disclosure
Liabilities, Fair Value Disclosure	635		200
Fair Value, Measurements, Recurring [Member] | Mortgage servicing rights [Member]
Assets, Fair Value Disclosure
Assets, Fair Value Disclosure	350		322
Fair Value, Measurements, Recurring [Member] | Mortgage servicing rights [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure
Assets, Fair Value Disclosure	$ 350		$ 322

[1] Actual maturities for these debt securities are dependent upon the interest rate environment and prepayments on the underlying loans.