FAIR VALUE MEASUREMENTS - Unobservable Inputs Used and Valuation Techniques (Details) - Level 3	Mar. 31, 2024	Dec. 31, 2023
Minimum | Discounted Cash Flow | Constant prepayment rate | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input	0.0576
Minimum | Discounted Cash Flow | Constant prepayment rate | Residential mortgages
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input		0.0670
Minimum | Discounted Cash Flow | Option adjusted spread | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input	3.98	3.98
Minimum | Internal Model | Pull through rate | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	0.2412	0.2490
Minimum | Internal Model | MSR value | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	0.0720	(0.0890)
Maximum | Discounted Cash Flow | Constant prepayment rate | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input	0.1758
Maximum | Discounted Cash Flow | Constant prepayment rate | Residential mortgages
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input		0.1455
Maximum | Discounted Cash Flow | Option adjusted spread | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input	10.58	10.58
Maximum | Internal Model | Pull through rate | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	1.0000	0.9970
Maximum | Internal Model | MSR value | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	1.5360	1.4124
Weighted Average | Discounted Cash Flow | Constant prepayment rate | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input	0.0696
Weighted Average | Discounted Cash Flow | Constant prepayment rate | Residential mortgages
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input		0.0723
Weighted Average | Discounted Cash Flow | Option adjusted spread | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input	6.32	6.30
Weighted Average | Internal Model | Pull through rate | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	0.7607	0.8034
Weighted Average | Internal Model | MSR value | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	1.0058	0.8804