FAIR VALUE - Valuation Methodology and Unobservable Inputs for Level 3 Assets (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($) item	Dec. 31, 2019 USD ($) item
Fair Value, Measurements, Nonrecurring [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans	$ 10,039	$ 12,121
Commercial and Industrial Loans [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Valuation Methodology	Collateral based measurements
Commercial and Industrial Loans [Member] | Fair Value, Measurements, Nonrecurring [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Commercial and Industrial Loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans	$ 7,334	$ 9,500
Commercial and Industrial Loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Minimum | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	7	1
Commercial and Industrial Loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Weighted Average | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths) | item	48	53
Commercial Real Estate and Multi-family Residential Loans [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Valuation Methodology	Collateral based measurements
Commercial Real Estate and Multi-family Residential Loans [Member] | Fair Value, Measurements, Nonrecurring [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Commercial Real Estate and Multi-family Residential Loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans	$ 1,527	$ 1,492
Commercial Real Estate and Multi-family Residential Loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Minimum | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	7	7
Commercial Real Estate and Multi-family Residential Loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Weighted Average | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths) | item	25	27
Consumer 1-4 Family Mortgage Loans [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Valuation Methodology	Collateral based measurements
Consumer 1-4 Family Mortgage Loans [Member] | Fair Value, Measurements, Nonrecurring [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Consumer 1-4 Family Mortgage Loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans	$ 1,088	$ 1,061
Consumer 1-4 Family Mortgage Loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Minimum | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	5	5
Consumer 1-4 Family Mortgage Loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Weighted Average | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths) | item	14	14
Agribusiness and Agricultural
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Valuation Methodology	Collateral based measurements
Agribusiness and Agricultural | Fair Value, Measurements, Nonrecurring [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Agribusiness and Agricultural | Fair Value, Measurements, Nonrecurring [Member] | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans	$ 90	$ 57
Agribusiness and Agricultural | Fair Value, Measurements, Nonrecurring [Member] | Weighted Average | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths) | item	39	61
Other consumer loans | Fair Value, Measurements, Nonrecurring [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Unobservable Inputs		Discount to reflect current market conditions and ultimate collectability
Other consumer loans | Fair Value, Measurements, Nonrecurring [Member] | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans		$ 11
Other consumer loans | Fair Value, Measurements, Nonrecurring [Member] | Weighted Average | Collateral Based Measurements | Measurement Input, Discount Rate
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths) | item		36