FAIR VALUE - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 1,630,971	$ 1,395,680
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	490,250	399,237
Available for sale securities	1,630,971	1,395,680
Loans held for investment, net of allowance	7,619,125	7,833,449
Accrued interest receivable	43,348	44,244
Deposits	8,725,303	8,873,467
Accrued interest payable	12,327	11,288
Borrowed funds	240,000	50,000
Subordinated debt	109,964	109,765
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	490,250	399,237
Available for sale securities	1,630,971	1,395,680
Loans held for investment, net of allowance	7,396,330	7,627,962
Accrued interest receivable	43,348	44,244
Deposits	8,719,835	8,866,645
Accrued interest payable	12,327	11,288
Borrowed funds	240,000	50,000
Subordinated debt	108,402	109,390
Estimated Fair Value | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	490,250	399,237
Available for sale securities	0	0
Loans held for investment, net of allowance	0	0
Accrued interest receivable	159	118
Deposits	0	0
Accrued interest payable	0	0
Borrowed funds	0	0
Subordinated debt	0	0
Estimated Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Available for sale securities	1,630,971	1,395,680
Loans held for investment, net of allowance	0	0
Accrued interest receivable	7,042	6,716
Deposits	8,719,835	8,866,645
Accrued interest payable	12,327	11,288
Borrowed funds	240,000	50,000
Subordinated debt	108,402	109,390
Estimated Fair Value | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Available for sale securities	0	0
Loans held for investment, net of allowance	7,396,330	7,627,962
Accrued interest receivable	36,147	37,410
Deposits	0	0
Accrued interest payable	0	0
Borrowed funds	0	0
Subordinated debt	$ 0	$ 0