Commitments and Contingencies - Summary of Contract Amounts of Credit-related Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	$ 112,410	$ 87,337
Credit Enhancement Under FHLB of Chicago Mortgage Partnership Finance Program [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	1,275	1,095
Commitments to Sell Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	6,178	635
Overdraft Protection Program Commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	3,702	3,758
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	159	150
Fixed Rate [Member] | Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	10,674	1,136
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	1,275	1,095
Fixed Rate [Member] | Commitments to Sell Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	6,178	635
Fixed Rate [Member] | Overdraft Protection Program Commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	3,702	3,758
Variable Rate [Member] | Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	101,736	86,201
Variable Rate [Member] | Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fixed Rate	$ 159	$ 150