Loans and Allowance for Loan Losses - Summary of Post-modification Balance of TDRs listed by Type of Modification (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post modification balance of TDRs	$ 462	$ 2,080	$ 757	$ 2,766
Interest only/principal deferred
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post modification balance of TDRs	0	1,305	0	1,305
Extended maturity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post modification balance of TDRs	0	35	0	35
Extended maturity and interest only/principal deferred
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post modification balance of TDRs	0	381	0	427
Court-ordered concession
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post modification balance of TDRs	0	359	295	999
Principal and interest deferred
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post modification balance of TDRs	$ 462	$ 0	$ 462	$ 0