Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Deferred income tax assets:
Deferred compensation	$ 295,006	$ 254,526
Net operating loss carryforward	1,333,553	2,183,138
Other real estate owned	26,804	2,688
Charitable contributions	0	64,038
State tax credits	198,221	176,462
Defined benefit obligations (non-qualified)	490,528	812,019
Director deferred fee practice	0	22,379
Non-accrual loans	126,915	108,320
Frozen pension accrual (tax qualified)	327,425	375,275
Unrealized loss on investment securities available-for-sale	64,467
Other	24,412	3,848
Total gross deferred tax assets	2,887,331	4,002,693
Less: Valuation allowance	(198,221)	(176,462)
Net deferred tax asset	2,689,110	3,826,231
Deferred income tax liabilities:
Premises and equipment	14,021	36,005
Allowance for loan losses	120,539	151,516
Unrealized gain on investment securities available-for-sale	0	138,905
Director fee plan	8,663
Other	3,863
Total gross deferred tax liabilities	147,086	326,426
Net deferred tax asset	$ 2,542,024	$ 3,499,805