ACCUMULATED OTHER COMPREHENSIVE LOSS - Summary of Components of AOCI (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income
Total equity	$ 790	$ 1,136	$ 2,779	$ 2,815
Foreign currency translation adjustment
Accumulated Other Comprehensive Income
Total equity	(2,236)	(2,046)
Pension and postretirement benefit plan adjustments, net of income taxes
Accumulated Other Comprehensive Income
Total equity	(45)	(40)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income
Total equity	$ (2,281)	$ (2,086)	$ (2,116)	$ (2,137)