Fair Value Measurements - Summary of Estimated Fair Value of Financial Instruments that are not Required to be Measured or Reported at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Financial assets:
Cash and cash equivalents (Level 1)	$ 31,449	$ 9,002	$ 35,220	$ 11,210
Loans (Level 3)	409,427	323,214
Financial liabilities:
Time Deposits (Level 3)	133,672	143,041
Short-term borrowings (Level 1)	0	41,667
Long-term borrowings (Level 3)	43,060	57,285
Subordinated Notes (Level 3)	19,973	19,970
Carrying Amount [Member] | Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash and cash equivalents (Level 1)	31,449	9,002
Accrued interest receivable (Level 1)	2,509	1,842
Federal Home Loan Bank stock (Level 1)	1,015	2,615
Financial liabilities:
Non-maturity deposits (Level 1)	238,381	140,013
Short-term borrowings (Level 1)	0	41,667
Accrued interest payable (Level 1)	81	414
Carrying Amount [Member] | Fair Value, Inputs, Level 3 [Member]
Financial assets:
Loans (Level 3)	409,427	323,214
Financial liabilities:
Time Deposits (Level 3)	133,672	143,041
Long-term borrowings (Level 3)	23,087	37,315
Subordinated Notes (Level 3)	20,000	20,000
Off-balance-sheet financial instruments (Level 3)	0	0
Fair Value [Member] | Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash and cash equivalents (Level 1)	31,449	9,002
Accrued interest receivable (Level 1)	2,509	1,842
Federal Home Loan Bank stock (Level 1)	1,015	2,615
Financial liabilities:
Non-maturity deposits (Level 1)	238,381	140,013
Short-term borrowings (Level 1)	0	41,667
Accrued interest payable (Level 1)	81	414
Fair Value [Member] | Fair Value, Inputs, Level 3 [Member]
Financial assets:
Loans (Level 3)	405,474	324,160
Financial liabilities:
Time Deposits (Level 3)	128,804	142,787
Long-term borrowings (Level 3)	23,087	37,738
Subordinated Notes (Level 3)	20,479	20,256
Off-balance-sheet financial instruments (Level 3)	$ 0	$ 0