PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized in Consolidated Balance Sheet [Abstract]
Postretirement benefit obligations other than pensions		$ (326,000,000)	$ (344,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Income) Loss [Abstract]
Total recognized in other comprehensive (income) loss		(115,000,000)		$ (847,000,000)
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	530,000,000
Service cost		0	0	0
Interest cost		14,000,000	15,000,000	19,000,000
Plan amendments		(2,000,000)	(34,000,000)
Actuarial (gains) losses		(16,000,000)	(110,000,000)
Benefits paid - OPEB		(35,000,000)	(37,000,000)
Benefit obligation at end of year		325,000,000	364,000,000	530,000,000
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	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		(325,000,000)	(364,000,000)
Amounts recognized in Consolidated Balance Sheet [Abstract]
Accrued Liabilities - Current		(40,000,000)	(62,000,000)
Postretirement benefit obligations other than pensions		(285,000,000)	(302,000,000)
Net amount recognized		(325,000,000)	(364,000,000)
Foreign plans excluded from postretirement benefits other than pensions		41,000,000	42,000,000
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Prior service (credit) cost		(166,000,000)	(226,000,000)
Net actuarial (gain) loss		(20,000,000)	(4,000,000)
Net amount recognized		(186,000,000)	(230,000,000)
Defined Benefit Plan Disclosure [Abstract]
Service cost		0	0	0
Interest cost		14,000,000	15,000,000	19,000,000
Amortization of prior service (credit) cost		(62,000,000)	(52,000,000)	(58,000,000)
Recognition of actuarial losses		0	3,000,000	13,000,000
Net periodic benefit (income) cost		(48,000,000)	(34,000,000)	(26,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Income) Loss [Abstract]
Actuarial (gains) losses		(16,000,000)	(110,000,000)	(14,000,000)
Prior service cost (credit)		(2,000,000)	(34,000,000)	91,000,000
Prior service credit recognized during year		62,000,000	52,000,000	58,000,000
Actuarial losses recognized during year		0	(3,000,000)	(13,000,000)
Total recognized in other comprehensive (income) loss		44,000,000	(95,000,000)	122,000,000
Total recognized in net periodic benefit (income) cost and other comprehensive (income) loss		(4,000,000)	(129,000,000)	96,000,000
Other Postretirement Benefits [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Abstract]
Amortization of prior service (credit) cost	(63,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Income) Loss [Abstract]
Net loss to be amortized	0
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	18,151,000,000
Service cost		82,000,000	140,000,000	172,000,000
Interest cost		613,000,000	573,000,000	586,000,000
Plan amendments		0	0
Actuarial (gains) losses		2,064,000,000	(1,111,000,000)
Benefits paid		(1,111,000,000)	(1,137,000,000)
Settlements and curtailments		(507,000,000)	0
Foreign currency translation		0	0
Other		1,000,000	(475,000,000)
Benefit obligation at end of year		17,283,000,000	16,141,000,000	18,151,000,000
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	18,985,000,000
Actual return on plan assets		3,458,000,000	(303,000,000)
Company contributions		45,000,000	34,000,000
Benefits paid		(1,111,000,000)	(1,137,000,000)
Settlements and curtailments		(507,000,000)	0
Foreign currency translation		0	0
Other		1,000,000	(470,000,000)
Fair value of plan assets at end of year		18,995,000,000	17,109,000,000	18,985,000,000
Funded status of plans		1,712,000,000	968,000,000
Amounts recognized in Consolidated Balance Sheet [Abstract]
Other Assets		2,069,000,000	1,295,000,000
Accrued Liabilities - Current		(32,000,000)	(27,000,000)
Other Liabilities - Noncurrent		(325,000,000)	(300,000,000)
Net amount recognized		1,712,000,000	968,000,000
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Prior service (credit) cost		(176,000,000)	(218,000,000)
Net actuarial (gain) loss		544,000,000	860,000,000
Net amount recognized		368,000,000	642,000,000
Defined Benefit Plan Disclosure [Abstract]
Service cost		82,000,000	140,000,000	172,000,000
Interest cost		613,000,000	573,000,000	586,000,000
Expected return on plan assets		(1,117,000,000)	(1,426,000,000)	(1,262,000,000)
Amortization of prior service (credit) cost		(42,000,000)	(43,000,000)	(43,000,000)
Recognition of actuarial losses		35,000,000	0	41,000,000
Settlements and curtailments		4,000,000	0	18,000,000
Net periodic benefit (income) cost		(425,000,000)	(756,000,000)	(488,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Income) Loss [Abstract]
Actuarial (gains) losses		(277,000,000)	619,000,000	(792,000,000)
Prior service cost (credit)		0	0	0
Prior service credit recognized during year		42,000,000	43,000,000	43,000,000
Actuarial losses recognized during year		(39,000,000)	0	(59,000,000)
Foreign currency translation		0	0	0
Total recognized in other comprehensive (income) loss		(274,000,000)	662,000,000	(808,000,000)
Total recognized in net periodic benefit (income) cost and other comprehensive (income) loss		(699,000,000)	(94,000,000)	(1,296,000,000)
UNITED STATES | Forecast [Member]
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Income) Loss [Abstract]
Net loss to be amortized	(42,000,000)
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	7,019,000,000
Service cost		22,000,000	26,000,000	40,000,000
Interest cost		142,000,000	143,000,000	147,000,000
Plan amendments		0	30,000,000
Actuarial (gains) losses		708,000,000	(356,000,000)
Benefits paid		(269,000,000)	(264,000,000)
Settlements and curtailments		0	(9,000,000)
Foreign currency translation		107,000,000	(342,000,000)
Other		5,000,000	(65,000,000)
Benefit obligation at end of year		6,897,000,000	6,182,000,000	7,019,000,000
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	7,151,000,000
Actual return on plan assets		863,000,000	(173,000,000)
Company contributions		62,000,000	137,000,000
Benefits paid		(269,000,000)	(264,000,000)
Settlements and curtailments		0	0
Foreign currency translation		165,000,000	(378,000,000)
Other		5,000,000	8,000,000
Fair value of plan assets at end of year		7,307,000,000	6,481,000,000	7,151,000,000
Funded status of plans		410,000,000	299,000,000
Amounts recognized in Consolidated Balance Sheet [Abstract]
Other Assets		1,196,000,000	1,094,000,000
Accrued Liabilities - Current		(13,000,000)	(12,000,000)
Other Liabilities - Noncurrent		(773,000,000)	(783,000,000)
Net amount recognized		410,000,000	299,000,000
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Prior service (credit) cost		21,000,000	20,000,000
Net actuarial (gain) loss		701,000,000	600,000,000
Net amount recognized		722,000,000	620,000,000
Defined Benefit Plan Disclosure [Abstract]
Service cost		22,000,000	26,000,000	40,000,000
Interest cost		142,000,000	143,000,000	147,000,000
Expected return on plan assets		(331,000,000)	(443,000,000)	(411,000,000)
Amortization of prior service (credit) cost		0	(1,000,000)	(1,000,000)
Recognition of actuarial losses		88,000,000	37,000,000	46,000,000
Settlements and curtailments		0	(3,000,000)	0
Net periodic benefit (income) cost		(79,000,000)	(241,000,000)	(179,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Income) Loss [Abstract]
Actuarial (gains) losses		176,000,000	250,000,000	(153,000,000)
Prior service cost (credit)		0	30,000,000	(1,000,000)
Prior service credit recognized during year		0	4,000,000	1,000,000
Actuarial losses recognized during year		(88,000,000)	(37,000,000)	(46,000,000)
Foreign currency translation		14,000,000	(34,000,000)	43,000,000
Total recognized in other comprehensive (income) loss		102,000,000	213,000,000	(156,000,000)
Total recognized in net periodic benefit (income) cost and other comprehensive (income) loss		$ 23,000,000	$ (28,000,000)	$ (335,000,000)
Foreign Plan [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Abstract]
Amortization of prior service (credit) cost	$ 0