RETIREMENT AND POSTRETIREMENT PLANS - Major assumptions utilized to determine the net periodic cost of the Employee Retirement Plan (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
BNB Bank Pension Plan
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate used for net periodic benefit cost	2.69%	2.33%
Discount rate used to determine benefit obligation at period end	4.98%	2.69%
Expected long-term return on plan assets used for net periodic benefit cost	7.25%	7.25%
Expected long-term return on plan assets used to determine benefit obligation at period end	7.25%	7.25%
Employee Retirement Plan
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate used for net periodic benefit cost	2.55%	2.15%	2.97%
Discount rate used to determine benefit obligation at period end	4.90%	2.55%	2.15%
Expected long-term return on plan assets used for net periodic benefit cost	7.00%	7.00%	7.00%
Expected long-term return on plan assets used to determine benefit obligation at period end	7.00%	7.00%	7.00%
RETIREMENT PLANS | Board Member Retirement Plan
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate used for net periodic benefit cost			2.60%
Discount rate used to determine benefit obligation at period end			1.55%
RETIREMENT PLANS | Outside Director Retirement Plan [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate used for net periodic benefit cost			2.68%
Discount rate used to determine benefit obligation at period end			1.69%
POSTRETIREMENT PLANS
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate used for net periodic benefit cost			2.69%
Discount rate used to determine benefit obligation at period end			0.29%