RETIREMENT AND POSTRETIREMENT PLANS - Net periodic benefit (credit) cost for the Employee Retirement Plan (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
BNB Bank Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 267	$ 223	$ 535	$ 371
Interest cost	195	303	390	552
Expected return on assets	(857)	(1,245)	(1,715)	(2,229)
Amortization of unrealized loss		206		412
Net periodic credit	(395)	(513)	(790)	(894)
Employee Retirement Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost	155	183	310	366
Expected return on assets	(490)	(428)	(980)	(856)
Amortization of unrealized loss	63	229	125	458
Net periodic credit	(272)	$ (16)	(545)	$ (32)
RETIREMENT PLANS
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 0		$ 0