PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amounts recognized in Consolidated Balance Sheet [Abstract]
Postretirement benefit obligations other than pensions	$ (242,000,000)	$ (326,000,000)
Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	325,000,000	364,000,000
Service cost	0	0	$ 0
Interest cost	8,000,000	14,000,000	15,000,000
Plan amendments	(65,000,000)	(2,000,000)
Actuarial (gains) losses	(8,000,000)	(16,000,000)
Benefits paid - OPEB	(31,000,000)	(35,000,000)
Benefit obligation at end of year	229,000,000	325,000,000	364,000,000
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Company contributions	0	0
Benefits paid - OPEB	0	0
Fair value of plan assets at end of year	0	0	0
Funded status of plans	(229,000,000)	(325,000,000)
Amounts recognized in Consolidated Balance Sheet [Abstract]
Accrued Liabilities - Current	(27,000,000)	(40,000,000)
Postretirement benefit obligations other than pensions	(202,000,000)	(285,000,000)
Net amount recognized	(229,000,000)	(325,000,000)
Foreign plans excluded from postretirement benefits other than pensions	40,000,000	41,000,000
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Prior service (credit) cost	(165,000,000)	(166,000,000)
Net actuarial (gain) loss	(28,000,000)	(20,000,000)
Net amount recognized	(193,000,000)	(186,000,000)
Defined Benefit Plan Disclosure [Abstract]
Service cost	0	0	0
Interest cost	8,000,000	14,000,000	15,000,000
Amortization of prior service (credit) cost	(66,000,000)	(62,000,000)	(52,000,000)
Recognition of actuarial losses	0	0	3,000,000
Net periodic benefit (income) cost	(58,000,000)	(48,000,000)	(34,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Income) Loss [Abstract]
Actuarial (gains) losses	(8,000,000)	(16,000,000)	(110,000,000)
Prior service cost (credit)	(65,000,000)	(2,000,000)	(34,000,000)
Prior service credit recognized during year	66,000,000	62,000,000	52,000,000
Actuarial losses recognized during year	0	0	(3,000,000)
Total recognized in other comprehensive (income) loss	(7,000,000)	44,000,000	(95,000,000)
Total recognized in net periodic benefit (income) cost and other comprehensive (income) loss	(65,000,000)	(4,000,000)	(129,000,000)
UNITED STATES
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	17,283,000,000	16,141,000,000
Service cost	99,000,000	82,000,000	140,000,000
Interest cost	461,000,000	613,000,000	573,000,000
Plan amendments	0	0
Actuarial (gains) losses	1,331,000,000	2,064,000,000
Benefits paid	(1,100,000,000)	(1,111,000,000)
Settlements and curtailments	(21,000,000)	(507,000,000)
Foreign currency translation	0	0
Other	1,000,000	1,000,000
Benefit obligation at end of year	18,054,000,000	17,283,000,000	16,141,000,000
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	18,995,000,000	17,109,000,000
Actual return on plan assets	2,475,000,000	3,458,000,000
Company contributions	46,000,000	45,000,000
Benefits paid	(1,100,000,000)	(1,111,000,000)
Settlements and curtailments	(21,000,000)	(507,000,000)
Foreign currency translation	0	0
Other	1,000,000	1,000,000
Fair value of plan assets at end of year	20,396,000,000	18,995,000,000	17,109,000,000
Funded status of plans	2,342,000,000	1,712,000,000
Amounts recognized in Consolidated Balance Sheet [Abstract]
Other Assets	2,695,000,000	2,069,000,000
Accrued Liabilities - Current	(29,000,000)	(32,000,000)
Other Liabilities - Noncurrent	(324,000,000)	(325,000,000)
Net amount recognized	2,342,000,000	1,712,000,000
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Prior service (credit) cost	(134,000,000)	(176,000,000)
Net actuarial (gain) loss	505,000,000	544,000,000
Net amount recognized	371,000,000	368,000,000
Defined Benefit Plan Disclosure [Abstract]
Service cost	99,000,000	82,000,000	140,000,000
Interest cost	461,000,000	613,000,000	573,000,000
Expected return on plan assets	(1,135,000,000)	(1,117,000,000)	(1,426,000,000)
Amortization of prior service (credit) cost	(42,000,000)	(42,000,000)	(43,000,000)
Recognition of actuarial losses	26,000,000	35,000,000	0
Settlements and curtailments	4,000,000	4,000,000	0
Net periodic benefit (income) cost	(587,000,000)	(425,000,000)	(756,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Income) Loss [Abstract]
Actuarial (gains) losses	(9,000,000)	(277,000,000)	619,000,000
Prior service cost (credit)	0	0	0
Prior service credit recognized during year	42,000,000	42,000,000	43,000,000
Actuarial losses recognized during year	(30,000,000)	(39,000,000)	0
Foreign currency translation	0	0	0
Total recognized in other comprehensive (income) loss	3,000,000	(274,000,000)	662,000,000
Total recognized in net periodic benefit (income) cost and other comprehensive (income) loss	(584,000,000)	(699,000,000)	(94,000,000)
Foreign Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	6,897,000,000	6,182,000,000
Service cost	23,000,000	22,000,000	26,000,000
Interest cost	106,000,000	142,000,000	143,000,000
Plan amendments	2,000,000	0
Actuarial (gains) losses	509,000,000	708,000,000
Benefits paid	(246,000,000)	(269,000,000)
Settlements and curtailments	0	0
Foreign currency translation	291,000,000	107,000,000
Other	88,000,000	5,000,000
Benefit obligation at end of year	7,670,000,000	6,897,000,000	6,182,000,000
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	7,307,000,000	6,481,000,000
Actual return on plan assets	918,000,000	863,000,000
Company contributions	116,000,000	62,000,000
Benefits paid	(246,000,000)	(269,000,000)
Settlements and curtailments	0	0
Foreign currency translation	253,000,000	165,000,000
Other	102,000,000	5,000,000
Fair value of plan assets at end of year	8,450,000,000	7,307,000,000	6,481,000,000
Funded status of plans	780,000,000	410,000,000
Amounts recognized in Consolidated Balance Sheet [Abstract]
Other Assets	1,688,000,000	1,196,000,000
Accrued Liabilities - Current	(14,000,000)	(13,000,000)
Other Liabilities - Noncurrent	(894,000,000)	(773,000,000)
Net amount recognized	780,000,000	410,000,000
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Prior service (credit) cost	23,000,000	21,000,000
Net actuarial (gain) loss	629,000,000	701,000,000
Net amount recognized	652,000,000	722,000,000
Defined Benefit Plan Disclosure [Abstract]
Service cost	23,000,000	22,000,000	26,000,000
Interest cost	106,000,000	142,000,000	143,000,000
Expected return on plan assets	(336,000,000)	(331,000,000)	(443,000,000)
Amortization of prior service (credit) cost	0	0	(1,000,000)
Recognition of actuarial losses	18,000,000	88,000,000	37,000,000
Settlements and curtailments	0	0	(3,000,000)
Net periodic benefit (income) cost	(189,000,000)	(79,000,000)	(241,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Income) Loss [Abstract]
Actuarial (gains) losses	(73,000,000)	176,000,000	250,000,000
Prior service cost (credit)	2,000,000	0	30,000,000
Prior service credit recognized during year	0	0	4,000,000
Actuarial losses recognized during year	(18,000,000)	(88,000,000)	(37,000,000)
Foreign currency translation	19,000,000	14,000,000	(34,000,000)
Total recognized in other comprehensive (income) loss	(70,000,000)	102,000,000	213,000,000
Total recognized in net periodic benefit (income) cost and other comprehensive (income) loss	$ (259,000,000)	$ 23,000,000	$ (28,000,000)