Employee Benefits - Schedule of Net Pension Cost and Funded Status (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Schedule Of Net Pension Cost And Funded Status [Line Items]
Net pension cost charged to salaries and employee benefits	$ 65	$ 54
Pentegra defined benefit plan funded status as of July 1	111.97%	113.64%
Contributions paid to the plan	$ 74	$ 53
Plan's Funded Status [Member]
Schedule Of Net Pension Cost And Funded Status [Line Items]
Pentegra defined benefit plan funded status as of July 1	88.99%	87.84%