Federal Home Loan Bank Advances and Other Borrowings - Summary of Advances from the FHLB were Outstanding (Detail) - FHLB advance [Member]	Dec. 31, 2020 USD ($)
Line Of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 9,515,477
Due on January 9,2023 with fixed rate 4.49% [Member]
Line Of Credit Facility [Line Items]
Line of Credit facility, Advance Date	Jan. 07, 2008
Line of Credit Facility, Maximum Borrowing Capacity	$ 208,334
Line Of Credit Facility, Interest Rate Type	Fixed
Line of Credit Facility, Interest Rate at Period End	4.49%
Line of Credit facility, Maturity	Jan. 09, 2023
Due on September 20,2022 with fixed rate 1.80% [Member]
Line Of Credit Facility [Line Items]
Line of Credit facility, Advance Date	Sep. 20, 2012
Line of Credit Facility, Maximum Borrowing Capacity	$ 450,000
Line Of Credit Facility, Interest Rate Type	Fixed
Line of Credit Facility, Interest Rate at Period End	1.80%
Line of Credit facility, Maturity	Sep. 20, 2022
Due on April 1,2025 with fixed rate 0.66% [Member]
Line Of Credit Facility [Line Items]
Line of Credit facility, Advance Date	Apr. 01, 2020
Line of Credit Facility, Maximum Borrowing Capacity	$ 4,333,333
Line Of Credit Facility, Interest Rate Type	Fixed
Line of Credit Facility, Interest Rate at Period End	0.66%
Line of Credit facility, Maturity	Apr. 01, 2025
Due on April 07, 2027 with fixed rate 0.79% [Member]
Line Of Credit Facility [Line Items]
Line of Credit facility, Advance Date	Apr. 07, 2020
Line of Credit Facility, Maximum Borrowing Capacity	$ 4,523,810
Line Of Credit Facility, Interest Rate Type	Fixed
Line of Credit Facility, Interest Rate at Period End	0.79%
Line of Credit facility, Maturity	Apr. 07, 2027