Commitments and Contingencies - Summary of Contract Amounts of Credit-related Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	$ 84,022	$ 78,507
Credit Enhancement Under FHLB of Chicago Mortgage Partnership Finance Program [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	894	1,214
Commitments to Sell Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	1,292	5,410
Overdraft Protection Program Commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	3,881	3,993
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	150	175
Fixed Rate [Member] | Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	3,391	21,586
Fixed Rate [Member] | Credit Enhancement Under FHLB of Chicago Mortgage Partnership Finance Program [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	894	1,214
Fixed Rate [Member] | Commitments to Sell Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	1,292	5,410
Fixed Rate [Member] | Overdraft Protection Program Commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	3,881	3,993
Variable Rate [Member] | Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	80,631	56,921
Variable Rate [Member] | Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	$ 150	$ 175