RETIREMENT BENEFITS - Assumptions Used (Details)	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2019	Dec. 31, 2018
U.S. | Postretirement Benefit Plans
Plan Assumptions - During the year
Discount rate	3.80%	3.90%
Plan Assumptions - At year end
Discount rate	3.35%		3.80%	4.20%
Non-U.S. plans | Pension Plans | Weighted Average
Plan Assumptions - During the year
Discount rate	4.74%	4.86%
Plan Assumptions - At year end
Discount rate	4.52%		4.74%	5.09%
Non-U.S. plans | Pension Plans | Minimum
Plan Assumptions - During the year
Discount rate	0.45%	0.75%
Plan Assumptions - At year end
Discount rate	0.30%		0.45%	0.75%
Non-U.S. plans | Pension Plans | Maximum
Plan Assumptions - During the year
Discount rate	10.30%	9.90%
Plan Assumptions - At year end
Discount rate	9.55%		10.30%	10.75%
Non-U.S. plans | Postretirement Benefit Plans
Plan Assumptions - During the year
Discount rate	10.30%	9.50%
Plan Assumptions - At year end
Discount rate	9.70%		10.30%	10.75%
Qualified plans | U.S. | Pension Plans
Plan Assumptions - During the year
Discount rate	3.85%	3.95%
Plan Assumptions - At year end
Discount rate	3.45%		3.85%	4.25%
Nonqualified plans | U.S. | Pension Plans
Plan Assumptions - During the year
Discount rate	3.90%	3.95%
Plan Assumptions - At year end
Discount rate	3.50%		3.90%	4.25%