POSTRETIREMENT BENEFIT PLANS - Assumptions (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Plans | Principal Pension Plans
Weighted-average benefit obligations assumptions
Discount rate	5.20%
Compensation increases	3.90%
Weighted-average benefit cost assumptions
Discount rate	5.50%
Expected rate of return on plan assets	7.00%
Pension Plans | Other Pension Plans
Weighted-average benefit obligations assumptions
Discount rate	4.50%	4.30%	1.90%
Compensation increases	3.10%	3.00%	2.80%
Weighted-average benefit cost assumptions
Discount rate	4.90%	1.90%	1.40%
Expected rate of return on plan assets	5.60%	6.30%	5.40%
OPEB Plans
Weighted-average benefit obligations assumptions
Discount rate	5.10%
Compensation increases	3.60%
Weighted-average benefit cost assumptions
Discount rate	5.40%
Expected rate of return on plan assets	0.00%