EQUITY (Other Comprehensive Income/(Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Other Comprehensive Income (Loss), before Tax [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	$ 63	$ 18	$ 102	$ 63
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(20)	(13)	(76)	20
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax	43	5	26	83
Pension and postretirement benefits - Actuarial gains/(losses), Pre-tax	(126)	(12)	(140)	100
Pension and postretirement benefits - Amortization, Pre-tax	12	14	45	50
Pension and postretirement benefits - Curtailments and settlements, Pre-Tax	1,550	26	1,643	95
Pension and postretirement benefits, Pre-tax	1,436	28	1,548	245
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Reclassification Adjustments and Tax			42	(36)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax			3	0
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax	6	4	45	(36)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax	10	(21)	39	(232)
Other Comprehensive Income/(Loss), Pre-tax	1,495	16	1,658	60
Other Comprehensive Income (Loss), Tax, Parenthetical Disclosures [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax	(8)	(2)	(12)	(6)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	3	2	10	(6)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax	(5)	0	(2)	(12)
Pension and postretirement benefits - Actuarial gains/(losses), Tax	27	3	30	(21)
Pension and postretirement benefits - Amortization, Tax	(2)	(3)	(8)	(9)
Pension and postretirement benefits - Curtailments and settlements, Tax	(345)	(6)	(366)	(21)
Pension and postretirement benefits, Tax	(320)	(6)	(344)	(51)
Other Comprehensive Income (Loss), Available-for-sale Securities, before Reclassification Adjustments, Tax			(2)	5
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax			0	0
Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax	(2)	(2)	(2)	5
Foreign currency translation, Tax	(10)	0	(11)	(5)
Other comprehensive income/(loss), Tax	(337)	(8)	(359)	(63)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	55	16	90	57
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	(17)	(11)	(66)	14
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax	38	5	24	71
Pension and postretirement benefits - Actuarial gains/(losses), After tax	(99)	(9)	(110)	79
Pension and postretirement benefits - Amortization, After tax	10	11	37	41
Pension and postretirement benefits - Curtailments and settlements, After tax	1,205	20	1,277	74
Pension and postretirement benefits, After tax	1,116	22	1,204	194
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Reclassification Adjustments, after Tax			40	(31)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax			3	0
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax	4	2	43	(31)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	0	(21)	28	(237)
Other Comprehensive Income/(Loss)	1,158	$ 8	1,299	$ (3)
Derivatives qualifying as cash flow hedges	75		75		$ 51
Pension and postretirement benefits	(898)		(898)		(2,102)
Available-for-sale securities	13		13		(30)
Foreign currency translation	(653)		(653)		(681)
Accumulated other comprehensive loss	$ (1,463)		$ (1,463)		$ (2,762)