Loans and Allowance for Credit Losses - Troubled Debt Restructured Loans and Commitments (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Abstract]
Accrual status	$ 7,120	$ 8,512	$ 7,542
Nonaccrual status	13,134	14,740	6,037
Total	20,254	23,252	13,579
Letters of Credit Outstanding, Amount	60	60	60
Unused lines of credit	16	11	163
Commitments Net	$ 76	$ 71	$ 223