RETIREMENT AND POSTRETIREMENT PLANS - 401(K) Plan - (Details) - 401 K Plan - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Maximum contribution by employee, for the calendar year	$ 23,000
Percentage of match for first 1% of employee contributions	100.00%
Percentage of employee contribution on which 100% match by employer	1.00%
Percentage of match on next 1% of employee contributions	50.00%
Common stock within the accounts of participants	$ 4,400,000
Total expense recognized as a component of salaries and employee benefits expense	$ 872,000	$ 936,000
Maximum
Defined Benefit Plan Disclosure [Line Items]
Percentage of employee contribution on which 50% match by employer	6.00%
Maximum Percentage of participating employee contribution	3.50%