REGULATORY CAPITAL MATTERS (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Actual, Ratio (as a percent)	4.5	7.0
Tier One Risk Based Capital to Risk Weighted Assets	6.0	8.5
Capital to Risk Weighted Assets	8.0	10.5
Common Equity Tier One Capital Ratio	4.5	7.0
Basel III
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Actual, Ratio (as a percent)	9.5	10.2
Tier One Risk Based Capital to Risk Weighted Assets	10.7	12.4
Capital to Risk Weighted Assets	13.4	15.4
For Capital Adequacy Purposes, Ratio (as a percent)	4.0	4.0
Additional capital conservation buffer (as a percentage)	2.50%
Common Equity Tier One Capital Ratio	9.5	10.2
BNB Bank | Basel III
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Actual, Ratio (as a percent)	12.5	12.5
Tier One Risk Based Capital to Risk Weighted Assets	12.5	12.5
Capital to Risk Weighted Assets	13.4	13.3
For Capital Adequacy Purposes, Ratio (as a percent)	4.0	4.0
Common Equity Tier One Capital Ratio	12.5	12.5