FAIR VALUE DISCLOSURES - Valuation Methodology and Unobservable Inputs for Level 3 Assets (Details) - Fair Value, Measurements, Nonrecurring $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Fair Value	$ 6,180	$ 6,364
Commercial and industrial loans:
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Fair Value	$ 5,069	$ 5,342
Valuation Methodology	Collateral based measurements	Collateral based measurements
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Commercial and industrial loans: | Average
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.65	0.65
Commercial and industrial loans: | Minimum
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.21	0.22
Commercial and industrial loans: | Maximum
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.99	0.99
Commercial Real Estate and Multifamily Residential
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Fair Value	$ 880	$ 791
Valuation Methodology	Collateral based measurements	Collateral based measurements
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Commercial Real Estate and Multifamily Residential | Average
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.46	0.51
Commercial Real Estate and Multifamily Residential | Minimum
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.34	0.34
Commercial Real Estate and Multifamily Residential | Maximum
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.68	0.68
Agri-business and agricultural loans
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Fair Value	$ 231	$ 231
Valuation Methodology	Collateral based measurements	Collateral based measurements
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Agri-business and agricultural loans | Average
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.36	0.35
Agri-business and agricultural loans | Minimum
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.03	0.03
Agri-business and agricultural loans | Maximum
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.68	0.68
Other Real Estate Owned
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Fair Value	$ 196	$ 196
Valuation Methodology	Appraisals	Appraisals
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Other Real Estate Owned | Average
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Average	0.38	0.38