LOANS - Summary of Risk Category of Loans by Class of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Risk Category Of Loans [Line Items]
Loans	$ 2,859,774	$ 2,816,464
Construction and land development
Risk Category Of Loans [Line Items]
Loans	627,178	591,541
Commercial real estate:
Risk Category Of Loans [Line Items]
Loans	997,958	993,912
Residential real estate:
Risk Category Of Loans [Line Items]
Loans	648,586	643,601
Commercial and industrial
Risk Category Of Loans [Line Items]
Loans	581,598	582,641
Consumer and other
Risk Category Of Loans [Line Items]
Loans	4,454	4,769
Pass
Risk Category Of Loans [Line Items]
Loans	2,806,649	2,764,188
Pass \| Construction and land development
Risk Category Of Loans [Line Items]
Loans	627,178	591,293
Pass \| Commercial and industrial
Risk Category Of Loans [Line Items]
Loans	543,565	539,442
Pass \| Consumer and other
Risk Category Of Loans [Line Items]
Loans	4,454	4,769
Special Mention
Risk Category Of Loans [Line Items]
Loans	5,431	3,013
Special Mention \| Construction and land development
Risk Category Of Loans [Line Items]
Loans	0	248
Special Mention \| Commercial and industrial
Risk Category Of Loans [Line Items]
Loans	600	943
Special Mention \| Consumer and other
Risk Category Of Loans [Line Items]
Loans	0	0
Substandard
Risk Category Of Loans [Line Items]
Loans	47,694	49,263
Substandard \| Construction and land development
Risk Category Of Loans [Line Items]
Loans	0	0
Substandard \| Commercial and industrial
Risk Category Of Loans [Line Items]
Loans	37,433	42,256
Substandard \| Consumer and other
Risk Category Of Loans [Line Items]
Loans	0	0
Nonfarm, nonresidential \| Commercial real estate:
Risk Category Of Loans [Line Items]
Loans	955,348	944,021
Nonfarm, nonresidential \| Pass \| Commercial real estate:
Risk Category Of Loans [Line Items]
Loans	946,120	941,260
Nonfarm, nonresidential \| Special Mention \| Commercial real estate:
Risk Category Of Loans [Line Items]
Loans	4,012	997
Nonfarm, nonresidential \| Substandard \| Commercial real estate:
Risk Category Of Loans [Line Items]
Loans	5,216	1,764
Other \| Commercial real estate:
Risk Category Of Loans [Line Items]
Loans	42,610	49,891
Other \| Pass \| Commercial real estate:
Risk Category Of Loans [Line Items]
Loans	42,610	49,891
Other \| Special Mention \| Commercial real estate:
Risk Category Of Loans [Line Items]
Loans	0	0
Other \| Substandard \| Commercial real estate:
Risk Category Of Loans [Line Items]
Loans	0	0
Closed-end 1-4 family \| Residential real estate:
Risk Category Of Loans [Line Items]
Loans	456,610	455,920
Closed-end 1-4 family \| Pass \| Residential real estate:
Risk Category Of Loans [Line Items]
Loans	453,892	452,363
Closed-end 1-4 family \| Special Mention \| Residential real estate:
Risk Category Of Loans [Line Items]
Loans	819	825
Closed-end 1-4 family \| Substandard \| Residential real estate:
Risk Category Of Loans [Line Items]
Loans	1,899	2,732
Other \| Residential real estate:
Risk Category Of Loans [Line Items]
Loans	191,976	187,681
Other \| Pass \| Residential real estate:
Risk Category Of Loans [Line Items]
Loans	188,830	185,170
Other \| Special Mention \| Residential real estate:
Risk Category Of Loans [Line Items]
Loans	0	0
Other \| Substandard \| Residential real estate:
Risk Category Of Loans [Line Items]
Loans	$ 3,146	$ 2,511

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