RETIREMENT AND POSTRETIREMENT PLANS - 401(K) Plan - (Details) - 401 K Plan - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Maximum contribution by employee, for the calendar year			$ 20,500
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	$ 8,000,000.0		$ 8,000,000.0
Total expense recognized as a component of salaries and employee benefits expense	$ 530,000	$ 609,000	$ 1,300,000	$ 1,300,000
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%