LOANS AND ALLOWANCE FOR LOAN LOSSES - Summary of Accruing and Nonaccrual TDRs and Related Loan Losses by Portfolio Type (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable Modifications [Line Items]
TDRs loans	$ 14,650	$ 1,483
Accruing
Financing Receivable Modifications [Line Items]
TDRs loans	8,017	1,020
Nonaccrual
Financing Receivable Modifications [Line Items]
TDRs loans	6,633	463
Mortgage loans on real estate | Construction and development
Financing Receivable Modifications [Line Items]
TDRs loans	262	507
Mortgage loans on real estate | Construction and development | Accruing
Financing Receivable Modifications [Line Items]
TDRs loans	262	220
Mortgage loans on real estate | Construction and development | Nonaccrual
Financing Receivable Modifications [Line Items]
TDRs loans	0	287
Mortgage loans on real estate | 1-4 Family
Financing Receivable Modifications [Line Items]
TDRs loans	826	976
Mortgage loans on real estate | 1-4 Family | Accruing
Financing Receivable Modifications [Line Items]
TDRs loans	665	800
Mortgage loans on real estate | 1-4 Family | Nonaccrual
Financing Receivable Modifications [Line Items]
TDRs loans	161	$ 176
Mortgage loans on real estate | Commercial real estate
Financing Receivable Modifications [Line Items]
TDRs loans	5,833
Mortgage loans on real estate | Commercial real estate | Accruing
Financing Receivable Modifications [Line Items]
TDRs loans	4,895
Mortgage loans on real estate | Commercial real estate | Nonaccrual
Financing Receivable Modifications [Line Items]
TDRs loans	938
Commercial and industrial
Financing Receivable Modifications [Line Items]
TDRs loans	7,729
Commercial and industrial | Accruing
Financing Receivable Modifications [Line Items]
TDRs loans	2,195
Commercial and industrial | Nonaccrual
Financing Receivable Modifications [Line Items]
TDRs loans	$ 5,534