OTHER BORROWINGS - Schedule of Other Borrowings (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Other Borrowings [Line Items]
Subordinated deferrable interest debentures	$ 129,817	$ 128,322
Other borrowings	1,209,553	1,875,736
Fixed Rate Advance due January 9, 2023; fixed interest rate of 4.150%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	300,000
Debt instrument, interest rate, effective percentage	4.15%
Fixed Rate Advance due January 9, 2023; fixed interest rate of 4.110%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	50,000
Debt instrument, interest rate, effective percentage	4.11%
Fixed Rate Advance due January 12, 2023; fixed interest rate of 4.140%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	50,000
Debt instrument, interest rate, effective percentage	4.14%
Fixed Rate Advance due January 13, 2023; fixed interest rate of 4.150%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	50,000
Debt instrument, interest rate, effective percentage	4.15%
Fixed Rate Advance due January 17, 2023; fixed interest rate of 4.170%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	350,000
Debt instrument, interest rate, effective percentage	4.17%
Fixed Rate Advance due January 17, 2023; fixed interest rate of 4.250%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	150,000
Debt instrument, interest rate, effective percentage	4.25%
Fixed Rate Advance due January 18, 2023; fixed interest rate of 4.260%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	200,000
Debt instrument, interest rate, effective percentage	4.26%
Fixed Rate Advance due January 19, 2023; fixed interest rate of 4.230%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	50,000
Debt instrument, interest rate, effective percentage	4.23%
Fixed Rate Advance due January 20, 2023; fixed interest rate of 4.220%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	150,000
Debt instrument, interest rate, effective percentage	4.22%
Fixed Rate Advance due January 27, 2023; fixed interest rate of 4.230%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 0	100,000
Debt instrument, interest rate, effective percentage	4.23%
Fixed Rate Advance due October 16, 2023; fixed interest rate of 5.460%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 75,000	0
Debt instrument, interest rate, effective percentage	5.46%
Fixed Rate Advance due October 16, 2023; fixed interest rate of 5.470%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 200,000	0
Debt instrument, interest rate, effective percentage	5.47%
Fixed Rate Advance due October 18, 2023; fixed interest rate of 5.470%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 150,000	0
Debt instrument, interest rate, effective percentage	5.47%
Fixed Rate Advance due October 18, 2023; fixed interest rate of 5.470%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 100,000	0
Debt instrument, interest rate, effective percentage	5.47%
Fixed Rate Advance due October 19, 2023; fixed interest rate of 5.470%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 75,000	0
Debt instrument, interest rate, effective percentage	5.47%
Fixed Rate Advance due October 20, 2023; fixed interest rate of 5.460%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 250,000	0
Debt instrument, interest rate, effective percentage	5.46%
Fixed Rate Advance due March 3, 2025; fixed interest rate of 1.208%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 15,000	15,000
Debt instrument, interest rate, effective percentage	1.208%
Fixed Rate Advance due March 2, 2027; fixed interest rate of 1.445%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 15,000	15,000
Debt instrument, interest rate, effective percentage	1.445%
Fixed Rate Advance due March 4, 2030; fixed interest rate of 1.606%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 15,000	15,000
Debt instrument, interest rate, effective percentage	1.606%
Fixed Rate Advance due December 9, 2030; fixed interest rate of 4.55%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 1,380	1,389
Debt instrument, interest rate, effective percentage	4.55%
Fixed Rate Advance due December 9, 2030; fixed interest rate of 4.55%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 956	961
Debt instrument, interest rate, effective percentage	4.55%
Principal Reducing Advance due September 29, 2031; fixed interest rate of 3.095%
Other Borrowings [Line Items]
Advance from correspondent bank	$ 1,166	1,275
Debt instrument, interest rate, effective percentage	3.095%
Subordinated notes payable due March 15, 2027 net of unamortized debt issuance cost of $0 and $551, respectively; fixed interest rate of 5.75% through March 14, 2022; variable interest rate thereafter at three-month LIBOR plus 3.616%
Other Borrowings [Line Items]
Subordinated deferrable interest debentures	$ 0	74,449
Debt instrument, interest rate, effective percentage	5.75%
Unamortized debt issuance expense	$ 0	551
Subordinated notes payable due March 15, 2027 net of unamortized debt issuance cost of $0 and $551, respectively; fixed interest rate of 5.75% through March 14, 2022; variable interest rate thereafter at three-month LIBOR plus 3.616% | London Interbank Offered Rate (LIBOR)
Other Borrowings [Line Items]
Basis spread on variable rate	3.616%
Subordinated notes payable due December 15, 2029 net of unamortized debt issuance cost of $1,350 and $1,680, respectively; fixed interest rate of 4.25% through December 14, 2024; variable interest rate thereafter at three-month SOFR plus 2.94%
Other Borrowings [Line Items]
Subordinated deferrable interest debentures	$ 106,650	118,320
Debt instrument, interest rate, effective percentage	4.25%
Unamortized debt issuance expense	$ 1,350	1,680
Subordinated notes payable due December 15, 2029 net of unamortized debt issuance cost of $1,350 and $1,680, respectively; fixed interest rate of 4.25% through December 14, 2024; variable interest rate thereafter at three-month SOFR plus 2.94% | Secured Overnight Financing Rate (SOFR)
Other Borrowings [Line Items]
Basis spread on variable rate	2.94%
Subordinated notes payable due May 31, 2030 net of unaccreted purchase accounting fair value adjustment of $814 and $906, respectively; fixed interest rate of 5.875% through May 31, 2025; variable interest rate thereafter at three-month LIBOR plus 3.63%
Other Borrowings [Line Items]
Subordinated deferrable interest debentures	$ 75,814	75,906
Debt instrument, interest rate, effective percentage	5.875%
Unaccreted purchase accounting fair value adjustment	$ 814	906
Subordinated notes payable due May 31, 2030 net of unaccreted purchase accounting fair value adjustment of $814 and $906, respectively; fixed interest rate of 5.875% through May 31, 2025; variable interest rate thereafter at three-month LIBOR plus 3.63% | London Interbank Offered Rate (LIBOR)
Other Borrowings [Line Items]
Basis spread on variable rate	3.63%
Subordinated notes payable due October 1, 2030 net of unamortized debt issuance cost of $1,413 and $1,564, respectively; fixed interest rate of 3.875% through September 30, 2025; variable interest rate thereafter at three-month SOFR plus 3.753%
Other Borrowings [Line Items]
Subordinated deferrable interest debentures	$ 108,587	108,436
Debt instrument, interest rate, effective percentage	3.875%
Unamortized debt issuance expense	$ 1,413	1,564
Subordinated notes payable due October 1, 2030 net of unamortized debt issuance cost of $1,413 and $1,564, respectively; fixed interest rate of 3.875% through September 30, 2025; variable interest rate thereafter at three-month SOFR plus 3.753% | Secured Overnight Financing Rate (SOFR)
Other Borrowings [Line Items]
Basis spread on variable rate	3.753%
Advance from correspondent bank due November 28, 2024; secured by a loan receivable; variable interest rate at one-month SOFR plus 2.50%
Other Borrowings [Line Items]
Other borrowings	$ 10,000	0
Advance from correspondent bank due November 28, 2024; secured by a loan receivable; variable interest rate at one-month SOFR plus 2.50% | Secured Overnight Financing Rate (SOFR)
Other Borrowings [Line Items]
Basis spread on variable rate	2.50%
Advance from correspondent bank due December 1, 2025; secured by a loan receivable; variable interest rate at one-month SOFR plus 2.65%
Other Borrowings [Line Items]
Other borrowings	$ 10,000	$ 0
Advance from correspondent bank due December 1, 2025; secured by a loan receivable; variable interest rate at one-month SOFR plus 2.65% | Secured Overnight Financing Rate (SOFR)
Other Borrowings [Line Items]
Basis spread on variable rate	2.65%