RETIREMENT AND POSTRETIREMENT PLANS - 401(K) Plan - (Details) - 401 K Plan - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Maximum contribution by employee, for the calendar year			$ 22,500
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	$ 4,800,000		$ 4,800,000
Total expense recognized as a component of salaries and employee benefits expense	$ 513,000	$ 509,000	$ 2,000,000.0	$ 1,800,000
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%