EQUITY - AOCI (Details) - USD ($) $ in Millions	3 Months Ended
EQUITY - AOCI (Details) - USD ($) $ in Millions	Mar. 31, 2021	Mar. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 6,069
Other comprehensive income (loss) before reclassifications	(237)	$ (784)
Amount reclassified from accumulated other comprehensive income (loss)	(1)	(3)
Ending Balance	6,637
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(6,246)	(5,624)
Ending Balance	(6,484)	(6,411)
Foreign Exchange Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(5,857)	(5,263)
Other comprehensive income (loss) before reclassifications	(235)	(835)
Amount reclassified from accumulated other comprehensive income (loss)	0	0
Ending Balance	(6,092)	(6,098)
Deferred Gains (Losses) on Hedging Activities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(215)	(170)
Other comprehensive income (loss) before reclassifications	(2)	51
Amount reclassified from accumulated other comprehensive income (loss)	(1)	(4)
Ending Balance	(218)	(123)
Pension and Other Postretirement Liability Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(174)	(191)
Other comprehensive income (loss) before reclassifications	0	0
Amount reclassified from accumulated other comprehensive income (loss)	0	1
Ending Balance	$ (174)	$ (190)

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.