OTHER BORROWINGS AND SUBORDINATED NOTES AND DEBENTURES - Schedule of Debt Components (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended	33 Months Ended
	Sep. 30, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2024	Mar. 31, 2018
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		$ 619,967	$ 619,967	$ 1,111,665
Fair Value Hedging
Debt Instrument [Line Items]
Valuation adjustments on hedged subordinated notes payable		(3,455)	(3,455)	0
FHLB advances, net of discount, due 2026 to 2032, 3.62% to 5.53%, secured by real estate loans
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		286,597	286,597	727,945
Other long-term debt
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		15,656	15,656	17,427
Total other borrowings
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		302,253	$ 302,253	745,372
Subordinated notes
Debt Instrument [Line Items]
Fixed rate (as percent)					5.00%
Subordinated notes | LIBOR
Debt Instrument [Line Items]
Floating rate (as percent)			2.15%
Subordinated notes | SOFR
Debt Instrument [Line Items]
Floating rate (as percent)	3.02%		0.26161%
Subordinated notes | Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly)
Debt Instrument [Line Items]
Long-term debt, gross		$ 0	$ 0	330,000
Fixed rate (as percent)		5.00%	5.00%
Subordinated notes | Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | LIBOR
Debt Instrument [Line Items]
Floating rate (as percent)		2.15%
Subordinated notes | Subordinated notes payable, due 10/1/2035, fixed-to-floating rate (fixed rate of 6.25% through 9/30/2030, floating rate of 3.02% above the three-month SOFR rate, reset quarterly)
Debt Instrument [Line Items]
Long-term debt, gross		$ 325,000	$ 325,000	0
Fixed rate (as percent)		6.25%	6.25%
Subordinated notes | Subordinated notes payable, due 10/1/2035, fixed-to-floating rate (fixed rate of 6.25% through 9/30/2030, floating rate of 3.02% above the three-month SOFR rate, reset quarterly) | SOFR
Debt Instrument [Line Items]
Floating rate (as percent)		3.02%
Subordinated notes | Subordinated notes payable, net of premium adjustments, due 7/31/2030, fixed-to-floating rate (fixed rate of 6.00% through 7/30/2025, floating rate of 5.92% above the three month SOFR rate, reset quarterly)
Debt Instrument [Line Items]
Long-term debt, gross		$ 0	$ 0	37,057
Fixed rate (as percent)		6.00%	6.00%
Subordinated notes | Subordinated notes payable, net of premium adjustments, due 7/31/2030, fixed-to-floating rate (fixed rate of 6.00% through 7/30/2025, floating rate of 5.92% above the three month SOFR rate, reset quarterly) | SOFR
Debt Instrument [Line Items]
Floating rate (as percent)		5.92%
Total subordinated notes and debentures
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		$ 317,714	$ 317,714	366,293
Unamortized debt issuance costs		$ (3,831)	$ (3,831)	$ (764)
Minimum | FHLB advances, net of discount, due 2026 to 2032, 3.62% to 5.53%, secured by real estate loans
Debt Instrument [Line Items]
Fixed rate (as percent)		3.62%	3.62%
Maximum | FHLB advances, net of discount, due 2026 to 2032, 3.62% to 5.53%, secured by real estate loans
Debt Instrument [Line Items]
Fixed rate (as percent)		5.53%	5.53%