RETIREMENT BENEFITS PLANS - Other Postretirement Benefits Plan Assumptions (Details) - Other postretirement benefits plans	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Assumptions used to determine benefit obligation at year-end (as a percent)
Discount rate	5.11%	5.46%	2.79%
Health care cost trend rate assumed for next year	7.70%	7.10%	7.45%
Ultimate health care cost trend rate	4.75%	4.75%	4.75%
Year ultimate health care cost trend rate is achieved	2033	2031	2031
Assumptions used to determine expense (as a percent)
Discount rate used to determine benefit obligation	5.46%	2.79%	2.44%
Discount rate used to determine service cost	5.53%	3.03%	2.76%
Discount rate used to determine interest cost	5.32%	2.24%	1.70%
Initial health care cost trend rate	7.10%	7.45%	7.38%
Ultimate health care cost trend rate	4.75%	4.75%	4.75%
Year ultimate health care cost trend rate is achieved	2031	2031	2030