FAIR VALUE MEASUREMENTS - Unobservable Inputs Used and Valuation Techniques (Details) - Level 3	Sep. 30, 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	0.0581
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
Minimum | Internal Model | Pull through rate | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	0.1714
Minimum | Internal Model | MSR value | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	0.0425
Maximum | Discounted Cash Flow | Constant prepayment rate | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights, measurement input	0.1426
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
Maximum | Internal Model | Pull through rate | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	0.9970
Maximum | Internal Model | MSR value | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	1.5304
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	0.0640
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	6.30
Weighted Average | Internal Model | Pull through rate | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	0.8227
Weighted Average | Internal Model | MSR value | Other derivative contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other derivative contracts, measurement input	0.9679