REGULATORY CAPITAL REQUIREMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Common equity tier 1 capital to risk weighted assets:
Actual, Ratio (as a percent)	7.00%
Total Capital (to risk weighted assets)
Actual, Ratio (as a percent)	10.50%
Tier 1 Capital (to risk weighted assets)
Actual, Ratio (as a percent)	8.50%
Basel III
Common equity tier 1 capital to risk weighted assets:
Actual, Amount	$ 397,800	$ 360,688
Actual, Ratio (as a percent)	10.20%	10.40%
Minimum Capital Adequacy Requirement, Amount	$ 176,121	$ 155,836
Minimum Capital Adequacy Requirement, Ratio (as a percent)	4.50%	4.50%
Minimum Capital Adequacy Requirement with Capital Conservation Buffer, Amount	$ 273,967	$ 220,767
Minimum Capital Adequacy Requirement with Capital Conservation Buffer (as a percent)	7.00%	6.375%
Total Capital (to risk weighted assets)
Actual, Amount	$ 510,862	$ 472,382
Actual, Ratio (as a percent)	13.10%	13.60%
Minimum Capital Adequacy Requirement, Amount	$ 313,105	$ 277,041
Minimum Capital Adequacy Requirement (as a percent)	8.00%	8.00%
Minimum Capital Adequacy Requirement with Capital Conservation Buffer, Amount	$ 410,950	$ 341,973
Minimum Capital Adequacy Requirement with Capital Conservation Buffer (as a percent)	10.50%	9.875%
Tier 1 Capital (to risk weighted assets)
Actual, Amount	$ 397,800	$ 360,688
Actual, Ratio (as a percent)	10.20%	10.40%
For Capital Adequacy Purposes, Amount	$ 234,828	$ 207,781
For Capital Adequacy Purposes, Ratio (as a percent)	6.00%	6.00%
Minimum Capital Adequacy Requirement with Capital Conservation Buffer, Amount	$ 332,674	$ 272,712
Minimum Capital Adequacy Requirement with Capital Conservation Buffer (as a percent)	8.50%	7.875%
Tier 1 Capital (to average assets)
Actual, Amount	$ 397,800	$ 360,688
Actual, Ratio (as a percent)	8.50%	8.10%
For Capital Adequacy Purposes, Amount	$ 187,386	$ 177,782
For Capital Adequacy Purposes, Ratio (as a percent)	4.00%	4.00%
BNB Bank (Bank) | Basel III
Common equity tier 1 capital to risk weighted assets:
Actual, Amount	$ 474,056	$ 438,963
Actual, Ratio (as a percent)	12.10%	12.70%
Minimum Capital Adequacy Requirement, Amount	$ 176,114	$ 155,831
Minimum Capital Adequacy Requirement, Ratio (as a percent)	4.50%	4.50%
Minimum Capital Adequacy Requirement with Capital Conservation Buffer, Amount	$ 273,954	$ 220,761
Minimum Capital Adequacy Requirement with Capital Conservation Buffer (as a percent)	7.00%	6.375%
Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 254,386	$ 225,089
Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (as a percent)	6.50%	6.50%
Total Capital (to risk weighted assets)
Actual, Amount	$ 507,118	$ 470,657
Actual, Ratio (as a percent)	13.00%	13.60%
Minimum Capital Adequacy Requirement, Amount	$ 313,091	$ 277,033
Minimum Capital Adequacy Requirement (as a percent)	8.00%	8.00%
Minimum Capital Adequacy Requirement with Capital Conservation Buffer, Amount	$ 410,932	$ 341,963
Minimum Capital Adequacy Requirement with Capital Conservation Buffer (as a percent)	10.50%	9.875%
Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 391,363	$ 346,291
Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions (as a percent)	10.00%	10.00%
Tier 1 Capital (to risk weighted assets)
Actual, Amount	$ 474,056	$ 438,963
Actual, Ratio (as a percent)	12.10%	12.70%
For Capital Adequacy Purposes, Amount	$ 234,818	$ 207,775
For Capital Adequacy Purposes, Ratio (as a percent)	6.00%	6.00%
Minimum Capital Adequacy Requirement with Capital Conservation Buffer, Amount	$ 332,659	$ 272,704
Minimum Capital Adequacy Requirement with Capital Conservation Buffer (as a percent)	8.50%	7.875%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 313,091	$ 277,033
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (as a percent)	8.00%	8.00%
Tier 1 Capital (to average assets)
Actual, Amount	$ 474,056	$ 438,963
Actual, Ratio (as a percent)	10.10%	9.90%
For Capital Adequacy Purposes, Amount	$ 187,377	$ 177,776
For Capital Adequacy Purposes, Ratio (as a percent)	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 234,222	$ 222,220
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (as a percent)	5.00%	5.00%