RETIREMENT BENEFITS - Assumptions Used (Details)	3 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021	Dec. 31, 2020
U.S. | Postretirement Benefit Plans
Plan Assumptions - During the year
Discount rate	2.85%	3.20%
Plan Assumptions - At period end
Discount rate	2.60%		2.85%	2.20%
Non-U.S. plans | Pension Plans | Weighted Average
Plan Assumptions - During the year
Discount rate	4.26%	4.38%
Plan Assumptions - At period end
Discount rate	4.23%		4.26%	3.60%
Non-U.S. plans | Pension Plans | Minimum
Plan Assumptions - During the year
Discount rate	0.25%	0.45%
Plan Assumptions - At period end
Discount rate	0.25%		0.25%	0.05%
Non-U.S. plans | Pension Plans | Maximum
Plan Assumptions - During the year
Discount rate	9.30%	9.45%
Plan Assumptions - At period end
Discount rate	9.25%		9.30%	8.15%
Non-U.S. plans | Postretirement Benefit Plans
Plan Assumptions - During the year
Discount rate	9.70%	9.75%
Plan Assumptions - At period end
Discount rate	9.50%		9.70%	8.55%
Qualified plans | U.S. | Pension Plans
Plan Assumptions - During the year
Discount rate	3.10%	3.20%
Plan Assumptions - At period end
Discount rate	2.75%		3.10%	2.45%
Nonqualified plans | U.S. | Pension Plans
Plan Assumptions - During the year
Discount rate	3.00%	3.25%
Plan Assumptions - At period end
Discount rate	2.70%		3.00%	2.35%