FAIR VALUE MEASURES - Carrying Amount and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Financial assets:
Cash and due from banks	$ 257,297	$ 230,470
Interest-bearing deposits in banks	1,104,897	936,834
Debt securities held-to-maturity	128,298	122,731
Financial liabilities:
Other borrowings	946,413	509,586
Subordinated deferrable interest debentures	131,312	130,315
Carrying Amount
Financial assets:
Cash and due from banks	257,297	230,470
Interest-bearing deposits in banks	1,104,897	936,834
Debt securities held-to-maturity	148,538	141,512
Loans, net	20,603,363	19,925,225
Financial liabilities:
Deposits	21,444,143	20,708,509
Other borrowings	946,413	509,586
Subordinated deferrable interest debentures	131,312	130,315
Fair Value
Financial assets:
Cash and due from banks	257,297	230,470
Interest-bearing deposits in banks	1,104,897	936,834
Debt securities held-to-maturity	128,298	122,731
Loans, net	20,064,808	19,332,899
Financial liabilities:
Deposits	21,446,565	20,707,463
Other borrowings	936,511	501,723
Subordinated deferrable interest debentures	142,058	141,407
Fair Value | Level 1
Financial assets:
Cash and due from banks	257,297	230,470
Interest-bearing deposits in banks	1,104,897	936,834
Debt securities held-to-maturity	0	0
Loans, net	0	0
Financial liabilities:
Deposits	0	0
Other borrowings	0	0
Subordinated deferrable interest debentures	0	0
Fair Value | Level 2
Financial assets:
Cash and due from banks	0	0
Interest-bearing deposits in banks	0	0
Debt securities held-to-maturity	128,298	122,731
Loans, net	0	0
Financial liabilities:
Deposits	21,446,565	20,707,463
Other borrowings	936,511	501,723
Subordinated deferrable interest debentures	142,058	141,407
Fair Value | Level 3
Financial assets:
Cash and due from banks	0	0
Interest-bearing deposits in banks	0	0
Debt securities held-to-maturity	0	0
Loans, net	20,064,808	19,332,899
Financial liabilities:
Deposits	0	0
Other borrowings	0	0
Subordinated deferrable interest debentures	$ 0	$ 0