Loans and Allowance for Loan Losses - Summary of Past Due Loan Portfolio Relates to Certain High-Risk Industries Impacted by COVID-19 (Detail) - High-Risk Industries [Member] - COVID-19 [Member] $ in Thousands	Dec. 31, 2020 USD ($) Borrower
Financing Receivable, Past Due [Line Items]
Number of Borrowers | Borrower	88
Loans past due | $	$ 57,767
Hotels and Motels [Member]
Financing Receivable, Past Due [Line Items]
Number of Borrowers | Borrower	15
Loans past due | $	$ 34,617
Bed and Breakfasts [Member]
Financing Receivable, Past Due [Line Items]
Number of Borrowers | Borrower	5
Loans past due | $	$ 2,739
All Other Traveler Accommodations [Member]
Financing Receivable, Past Due [Line Items]
Number of Borrowers | Borrower	5
Loans past due | $	$ 4,392
Full-Service Restaurants [Member]
Financing Receivable, Past Due [Line Items]
Number of Borrowers | Borrower	15
Loans past due | $	$ 4,202
Limited-Service Restaurants [Member]
Financing Receivable, Past Due [Line Items]
Number of Borrowers | Borrower	12
Loans past due | $	$ 4,737
Religious Organizations [Member]
Financing Receivable, Past Due [Line Items]
Number of Borrowers | Borrower	36
Loans past due | $	$ 7,080