FAIR VALUE OF FINANCIAL INSTRUMENTS- Quantitative Information (Details) $ in Thousands	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value	$ 656,254	$ 649,433
Non recurring member
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan servicing rights	44,566	53,824
Nonperforming loans	15,972	14,693
Level 3 | Recurring member | Net market price | Corporate Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value	$ 925	$ 955
Valuation technique for corporate securities	us-gaap:ValuationTechniqueConsensusPricingModelMember	us-gaap:ValuationTechniqueConsensusPricingModelMember
Level 3 | Non recurring member
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan servicing rights	$ 44,566	$ 53,824
Nonperforming loans	$ 522	$ 2,175
Level 3 | Non recurring member | Commercial MSR
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Valuation technique for servicing asset	us-gaap:ValuationTechniqueDiscountedCashFlowMember	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Level 3 | Non recurring member | SBA servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Valuation technique for servicing asset	us-gaap:ValuationTechniqueDiscountedCashFlowMember	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Level 3 | Non recurring member | MSR held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Valuation technique for servicing asset	us-gaap:ValuationTechniqueDiscountedCashFlowMember	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Level 3 | Non recurring member | Discounted cash flow | Commercial MSR
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan servicing rights	$ 43,497	$ 52,693
Level 3 | Non recurring member | Discounted cash flow | SBA servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan servicing rights	1,069	1,131
Level 3 | Non recurring member | Discounted cash flow | MSR held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan servicing rights	1,460	1,972
Level 3 | Non recurring member | Fair value of collateral | Impaired loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Nonperforming loans	$ 522	$ 2,175
Minimum | Level 3 | Recurring member | Net market price | Corporate Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for corporate securities	(1.5)	(2.0)
Minimum | Level 3 | Non recurring member | Measurement Input Discount Rate For Type Of Property Age Of Appraisal And Current Status [Member] | Impaired loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for nonperforming loans		0.0432
Minimum | Level 3 | Non recurring member | Discounted cash flow | Prepayment speed | Commercial MSR
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	8.00	8.00
Minimum | Level 3 | Non recurring member | Discounted cash flow | Prepayment speed | SBA servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	8.31	8.31
Minimum | Level 3 | Non recurring member | Discounted cash flow | Prepayment speed | MSR held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	14.04	8.64
Minimum | Level 3 | Non recurring member | Discounted cash flow | Discount rate | Commercial MSR
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	10.00	10.00
Minimum | Level 3 | Non recurring member | Discounted cash flow | Discount rate | MSR held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	9.00	9.50
Maximum | Level 3 | Recurring member | Net market price | Corporate Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for corporate securities	2.0	2.5
Maximum | Level 3 | Non recurring member | Measurement Input Discount Rate For Type Of Property Age Of Appraisal And Current Status [Member] | Impaired loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for nonperforming loans		0.0800
Maximum | Level 3 | Non recurring member | Discounted cash flow | Prepayment speed | Commercial MSR
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	22.50	18.00
Maximum | Level 3 | Non recurring member | Discounted cash flow | Prepayment speed | SBA servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	9.21	9.21
Maximum | Level 3 | Non recurring member | Discounted cash flow | Prepayment speed | MSR held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	26.28	26.28
Maximum | Level 3 | Non recurring member | Discounted cash flow | Discount rate | Commercial MSR
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	27.00	14.00
Maximum | Level 3 | Non recurring member | Discounted cash flow | Discount rate | MSR held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	11.50	12.50
Weighted average | Level 3 | Recurring member | Net market price | Corporate Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for corporate securities	(1.0)	(1.5)
Weighted average | Level 3 | Non recurring member | Discounted cash flow | Prepayment speed | Commercial MSR
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	(8.38)	(8.20)
Weighted average | Level 3 | Non recurring member | Discounted cash flow | Prepayment speed | SBA servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	(8.60)	(8.60)
Weighted average | Level 3 | Non recurring member | Discounted cash flow | Prepayment speed | MSR held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	(16.92)	(12.42)
Weighted average | Level 3 | Non recurring member | Discounted cash flow | Discount rate | Commercial MSR
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	(11.43)	(11.02)
Weighted average | Level 3 | Non recurring member | Discounted cash flow | Discount rate | SBA servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	(11.70)	(11.70)
Weighted average | Level 3 | Non recurring member | Discounted cash flow | Discount rate | MSR held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for servicing asset	(10.13)	(10.75)
Weighted average | Level 3 | Non recurring member | Fair value of collateral | Measurement Input Discount Rate For Type Of Property Age Of Appraisal And Current Status [Member] | Impaired loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for nonperforming loans	(4.50)	(5.22)