LOANS - Troubled Debt Restructurings (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	$ 5,089,800,000	$ 3,774,157,000	$ 3,719,000,000
Past Due 90 Days or More and Still Accruing	53,000	289,000
Nonaccrual	12,489,000	10,430,000
Total		21,751,000
Allowance for TDRs		841,000
Financing receivable, total		841,000
Commercial, financial and agriculture
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	788,598,000	536,192,000
Past Due 90 Days or More and Still Accruing	32,000	0
Nonaccrual	315,000	19,000
Total		49,000
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	2,995,803,000	2,135,263,000
Past Due 90 Days or More and Still Accruing	21,000	0
Nonaccrual	8,985,000	7,445,000
Total		19,682,000
Consumer real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	1,247,568,000	1,058,999,000
Past Due 90 Days or More and Still Accruing	0	289,000
Nonaccrual	3,135,000	2,965,000
Total		2,006,000
Consumer installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	57,831,000	43,703,000
Past Due 90 Days or More and Still Accruing	0	0
Nonaccrual	54,000	1,000
Total		14,000
Financial Asset, Not Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment		14,701,000
Allowance for TDRs		350,000
Financial Asset, Not Past Due | Commercial, financial and agriculture
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment		49,000
Financial Asset, Not Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment		13,561,000
Financial Asset, Not Past Due | Consumer real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment		1,077,000
Financial Asset, Not Past Due | Consumer installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment		14,000
Financial Asset, Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	$ 0	0
Past Due 30-89		0
Past Due 90 Days or More and Still Accruing		0
Nonaccrual		7,050,000
Financing receivable allowance for credit losses current nonaccrual status		491,000
Financial Asset, Past Due | Commercial, financial and agriculture
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due 30-89		0
Past Due 90 Days or More and Still Accruing		0
Nonaccrual		0
Financial Asset, Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due 30-89		0
Past Due 90 Days or More and Still Accruing		0
Nonaccrual		6,121,000
Financial Asset, Past Due | Consumer real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due 30-89		0
Past Due 90 Days or More and Still Accruing		0
Nonaccrual		929,000
Financial Asset, Past Due | Consumer installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due 30-89		0
Past Due 90 Days or More and Still Accruing		0
Nonaccrual		$ 0