REGULATORY CAPITAL MATTERS - Schedule of the Company's and Bank's actual capital amounts and ratios (Details) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Common equity Tier 1 capital / % of risk weighted assets
Actual, Ratio (as a percent)	0.045	0.070
Tier 1 Capital / % of risk weighted assets
Actual, Ratio (as a percent)	0.060	0.085
Total Capital / % of risk weighted assets
Actual, Ratio (as a percent)	0.080	0.105
Basel III
Tier 1 Capital / % of average total assets
Actual, Amount	$ 1,103,498	$ 1,037,235
Actual, Ratio (as a percent)	0.085	0.085
For Capital Adequacy Purposes, Amount	$ 517,914	$ 490,420
For Capital Adequacy Purposes, Minimum Ratio (as a percent)	0.040	0.040
Common equity Tier 1 capital / % of risk weighted assets
Actual, Amount	$ 986,928	$ 920,666
Actual, Ratio (as a percent)	0.092	0.095
For Capital Adequacy Purposes, Amount	$ 485,243	$ 436,700
For Capital Adequacy Purposes, Minimum Ratio (as a percent)	0.045%	0.045%
Tier 1 Capital / % of risk weighted assets
Actual, Amount	$ 1,103,498	$ 1,037,235
Actual, Ratio (as a percent)	0.102	0.107
For Capital Adequacy Purposes, Amount	$ 646,990	$ 582,267
For Capital Adequacy Purposes, Minimum Ratio (as a percent)	0.060	0.060
Total Capital / % of risk weighted assets
Actual, Amount	$ 1,390,272	$ 1,304,891
Actual, Ratio (as a percent)	0.129	0.134
For Capital Adequacy Purposes, Amount	$ 862,654	$ 776,356
For Capital Adequacy Purposes, Minimum Ratio (as a percent)	0.080	0.080
BNB Bank | Basel III
Tier 1 Capital / % of average total assets
Actual, Amount	$ 1,286,656	$ 1,215,586
Actual, Ratio (as a percent)	0.100	0.100
For Capital Adequacy Purposes, Amount	$ 517,606	$ 488,506
For Capital Adequacy Purposes, Minimum Ratio (as a percent)	0.040	0.040
To Be Categorized as "Well Capitalized", Amount	$ 647,008	$ 610,633
To Be Categorized as "Well Capitalized", Minimum Ratio (as a percent)	0.050	0.050
Common equity Tier 1 capital / % of risk weighted assets
Actual, Amount	$ 1,286,656	$ 1,215,586
Actual, Ratio (as a percent)	0.119	0.125
For Capital Adequacy Purposes, Amount	$ 485,062	$ 436,539
For Capital Adequacy Purposes, Minimum Ratio (as a percent)	0.045%	0.045%
To Be Categorized as "Well Capitalized", Amount	$ 700,645	$ 630,557
To Be Categorized as "Well Capitalized", Minimum Ratio (as a percent)	0.065%	0.065%
Tier 1 Capital / % of risk weighted assets
Actual, Amount	$ 1,286,656	$ 1,215,586
Actual, Ratio (as a percent)	0.119	0.125
For Capital Adequacy Purposes, Amount	$ 646,749	$ 582,052
For Capital Adequacy Purposes, Minimum Ratio (as a percent)	0.060	0.060
To Be Categorized as "Well Capitalized", Amount	$ 862,332	$ 776,070
To Be Categorized as "Well Capitalized", Minimum Ratio (as a percent)	0.080	0.080
Total Capital / % of risk weighted assets
Actual, Amount	$ 1,373,431	$ 1,304,242
Actual, Ratio (as a percent)	0.127	0.134
For Capital Adequacy Purposes, Amount	$ 862,332	$ 776,070
For Capital Adequacy Purposes, Minimum Ratio (as a percent)	0.080	0.080
To Be Categorized as "Well Capitalized", Amount	$ 1,077,915	$ 970,087
To Be Categorized as "Well Capitalized", Minimum Ratio (as a percent)	0.100	0.100