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FAIR VALUE - Unobservable Inputs Used to Measure Fair Value (Details) $ in Thousands	Sep. 30, 2025 USD ($)	Jun. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS, Fair value	$ 3,490,478		$ 3,065,251
Interest rate lock commitments, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate lock commitments, net	277	$ 0	0
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS, Fair value	3,490,478		3,065,251
Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities AFS, Fair value	1,659		$ 0
Recurring \| Level 3 \| Interest rate lock commitments, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate lock commitments, net	$ 277
Implied spread to benchmark interest rate curve \| Minimum \| Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Implied spread to benchmark interest rate curve	0.0225
Implied spread to benchmark interest rate curve \| Maximum \| Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Implied spread to benchmark interest rate curve	0.0225
Implied spread to benchmark interest rate curve \| Weighted Average \| Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Implied spread to benchmark interest rate curve	0.0225
Fall-out factor \| Minimum \| Recurring \| Level 3 \| Interest rate lock commitments, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fall-out factor/Value of servicing	0.0110
Fall-out factor \| Maximum \| Recurring \| Level 3 \| Interest rate lock commitments, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fall-out factor/Value of servicing	0.2454
Fall-out factor \| Weighted Average \| Recurring \| Level 3 \| Interest rate lock commitments, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fall-out factor/Value of servicing	0.1504
Value of servicing \| Minimum \| Recurring \| Level 3 \| Interest rate lock commitments, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fall-out factor/Value of servicing	0.0064
Value of servicing \| Maximum \| Recurring \| Level 3 \| Interest rate lock commitments, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fall-out factor/Value of servicing	0.0149
Value of servicing \| Weighted Average \| Recurring \| Level 3 \| Interest rate lock commitments, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fall-out factor/Value of servicing	0.0118