FAIR VALUE MEASURES - Fair Value Measurements of Assets Measured at Fair Value on Non-Recurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	$ 258,145	$ 251,125
Collateral-dependent loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	25,510	44,181
Other real estate owned
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	399
Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	232,236	206,944
Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Level 1 | Collateral-dependent loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Level 1 | Other real estate owned
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0
Level 1 | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Level 2 | Collateral-dependent loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Level 2 | Other real estate owned
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0
Level 2 | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	0	0
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	258,145	251,125
Level 3 | Collateral-dependent loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	25,510	44,181
Level 3 | Other real estate owned
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	399
Level 3 | Mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets at fair value	$ 232,236	$ 206,944