FINANCIAL DERIVATIVES - Schedule of Net Income/(Expense) Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Derivative Instruments, Gain (Loss) [Line Items]
Investment securities and cash equivalents	$ 215,222	$ 213,983	$ 418,631	$ 423,633
Loans	235,038	185,039	447,590	356,803
Total Interest Expense	(332,185)	(302,225)	(646,750)	(592,700)
Gains/(losses) on financial derivatives	224	80	1,364	(2,556)
Designated as hedge
Derivative Instruments, Gain (Loss) [Line Items]
Investment securities and cash equivalents	215,222	213,983	418,631	423,633
Loans	235,038	185,039	447,590	356,803
Total Interest Expense	(332,185)	(302,225)	(646,750)	(592,700)
Gains/(losses) on financial derivatives	224	80	1,364	(2,556)
Total	118,299	96,877	220,835	185,180
Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(27,449)	25,239	(11,557)	111,787
Net effects of fair value hedging relationships	21,216	16,439	41,569	30,572
Designated as hedge | Fair value hedges: | Income Statement Location [Axis]: us-gaap:GainLossOnDerivativeInstrumentsNetPretax
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	0	0	0	0
Net effects of fair value hedging relationships	0	0	0	0
Designated as hedge | Fair value hedges: | Income Statement Location [Axis]: us-gaap:InterestAndDividendIncomeSecurities
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(53,350)	57,040	(83,238)	173,036
Net effects of fair value hedging relationships	15,626	29,311	31,778	57,956
Designated as hedge | Fair value hedges: | Income Statement Location [Axis]: us-gaap:InterestAndFeeIncomeLoansAndLeases
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(18,858)	8,860	(20,992)	53,840
Net effects of fair value hedging relationships	8,287	13,332	16,354	26,142
Designated as hedge | Fair value hedges: | Income Statement Location [Axis]: us-gaap:InterestExpenseOperating
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	44,759	(40,661)	92,673	(115,089)
Net effects of fair value hedging relationships	(2,697)	(26,204)	(6,563)	(53,526)
Designated as hedge | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Interest settlements reclassified from AOCI into net income on derivatives	2,460	3,746	4,930	7,571
Net effects of cash flow hedges	2,460	3,746	4,930	7,571
Designated as hedge | Cash flow hedges: | Income Statement Location [Axis]: us-gaap:GainLossOnDerivativeInstrumentsNetPretax
Derivative Instruments, Gain (Loss) [Line Items]
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Net effects of cash flow hedges	0	0	0	0
Designated as hedge | Cash flow hedges: | Income Statement Location [Axis]: us-gaap:InterestAndDividendIncomeSecurities
Derivative Instruments, Gain (Loss) [Line Items]
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Net effects of cash flow hedges	0	0	0	0
Designated as hedge | Cash flow hedges: | Income Statement Location [Axis]: us-gaap:InterestAndFeeIncomeLoansAndLeases
Derivative Instruments, Gain (Loss) [Line Items]
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Net effects of cash flow hedges	0	0	0	0
Designated as hedge | Cash flow hedges: | Income Statement Location [Axis]: us-gaap:InterestExpenseOperating
Derivative Instruments, Gain (Loss) [Line Items]
Interest settlements reclassified from AOCI into net income on derivatives	2,460	3,746	4,930	7,571
Net effects of cash flow hedges	2,460	3,746	4,930	7,571
Designated as hedge | Interest Rate Swap | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	28,338	(22,530)	12,808	(107,979)
Amounts related to interest settlements on derivatives	20,327	13,730	40,318	26,764
Designated as hedge | Interest Rate Swap | Fair value hedges: | Income Statement Location [Axis]: us-gaap:GainLossOnDerivativeInstrumentsNetPretax
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	0	0	0	0
Amounts related to interest settlements on derivatives	0	0	0	0
Designated as hedge | Interest Rate Swap | Fair value hedges: | Income Statement Location [Axis]: us-gaap:InterestAndDividendIncomeSecurities
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	53,231	(56,736)	82,704	(173,231)
Amounts related to interest settlements on derivatives	15,745	29,007	32,312	58,151
Designated as hedge | Interest Rate Swap | Fair value hedges: | Income Statement Location [Axis]: us-gaap:InterestAndFeeIncomeLoansAndLeases
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	19,237	(8,027)	21,321	(52,581)
Amounts related to interest settlements on derivatives	7,908	12,499	16,025	24,883
Designated as hedge | Interest Rate Swap | Fair value hedges: | Income Statement Location [Axis]: us-gaap:InterestExpenseOperating
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(44,130)	42,233	(91,217)	117,833
Amounts related to interest settlements on derivatives	(3,326)	(27,776)	(8,019)	(56,270)
No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	224	80	1,364	(2,556)
No hedge designation | Income Statement Location [Axis]: us-gaap:GainLossOnDerivativeInstrumentsNetPretax
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	224	80	1,364	(2,556)
No hedge designation | Income Statement Location [Axis]: us-gaap:InterestAndDividendIncomeSecurities
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
No hedge designation | Income Statement Location [Axis]: us-gaap:InterestAndFeeIncomeLoansAndLeases
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
No hedge designation | Income Statement Location [Axis]: us-gaap:InterestExpenseOperating
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
No hedge designation | Interest Rate Swap
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	139	(834)	(822)	(3,537)
Interest expense on interest rate swaps	556	(208)	1,525	110
No hedge designation | Interest Rate Swap | Income Statement Location [Axis]: us-gaap:GainLossOnDerivativeInstrumentsNetPretax
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	139	(834)	(822)	(3,537)
Interest expense on interest rate swaps	556	(208)	1,525	110
No hedge designation | Interest Rate Swap | Income Statement Location [Axis]: us-gaap:InterestAndDividendIncomeSecurities
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Interest expense on interest rate swaps	0	0	0	0
No hedge designation | Interest Rate Swap | Income Statement Location [Axis]: us-gaap:InterestAndFeeIncomeLoansAndLeases
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Interest expense on interest rate swaps	0	0	0	0
No hedge designation | Interest Rate Swap | Income Statement Location [Axis]: us-gaap:InterestExpenseOperating
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Interest expense on interest rate swaps	0	0	0	0
No hedge designation | Treasury futures
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	(471)	1,122	661	871
No hedge designation | Treasury futures | Income Statement Location [Axis]: us-gaap:GainLossOnDerivativeInstrumentsNetPretax
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	(471)	1,122	661	871
No hedge designation | Treasury futures | Income Statement Location [Axis]: us-gaap:InterestAndDividendIncomeSecurities
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
No hedge designation | Treasury futures | Income Statement Location [Axis]: us-gaap:InterestAndFeeIncomeLoansAndLeases
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
No hedge designation | Treasury futures | Income Statement Location [Axis]: us-gaap:InterestExpenseOperating
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	$ 0	$ 0	$ 0	$ 0