RETIREMENT BENEFITS - Funded Status and Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
U.S. Plans | Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year			$ 12,766		$ 12,766
Benefits earned during the period	$ 0			$ 0	0	$ 0
Interest cost on benefit obligation	120			87	311	264
Change in plan assets
Plan assets at fair value at beginning of year			12,977		12,977
Net amount recognized at period end
Benefit asset	941				941
Benefit liability	(522)				(522)
Net amount recognized on the balance sheet—Significant Plans	419				419
Amounts recognized in AOCI at period end(5)
Prior service (expense) benefit	0				0
Net actuarial (loss) gain	(6,438)				(6,438)
Net amount recognized in equity-pretax	(6,438)				(6,438)
Accumulated benefit obligation at period end—Significant Plans	9,705				9,705
U.S. Plans | Pension Plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year			23		23
Change in plan assets
Plan assets at fair value at beginning of year			0		0
U.S. Plans | Pension Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	10,458		12,743		12,743
Quarter activity		$ (1,051)	(1,234)
Benefits earned during the period	0
Interest cost on benefit obligation	120
Actuarial (gain)	(642)
Benefits paid, net of participants’ contributions and government subsidy	(230)
Settlement (gain)	0
Foreign exchange impact and other	0
Projected benefit obligation at period end—Significant Plans	9,706	10,458			9,706
Change in plan assets
Plan assets at fair value at beginning of year	10,839		12,977		12,977
Quarterly activity		(1,108)	(1,030)
Actual return on plan assets	(497)
Company contributions, net of reimbursements	13
Benefits paid, net of participants’ contributions and government subsidy	(230)
Settlement gain	0
Foreign exchange impact and other	0
Plan assets at fair value at period end—Significant Plans	10,125	10,839			10,125
Funded status of the Significant Plans	419				419
U.S. Plans | Postretirement Benefit Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year			501		501
Benefits earned during the period	0			0	0	0
Interest cost on benefit obligation	4			3	11	9
Change in plan assets
Plan assets at fair value at beginning of year			319		319
Net amount recognized at period end
Benefit asset	0				0
Benefit liability	(124)				(124)
Net amount recognized on the balance sheet—Significant Plans	(124)				(124)
Amounts recognized in AOCI at period end(5)
Prior service (expense) benefit	85				85
Net actuarial (loss) gain	127				127
Net amount recognized in equity-pretax	212				212
Accumulated benefit obligation at period end—Significant Plans	374				374
U.S. Plans | Postretirement Benefit Plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year			0		0
Change in plan assets
Plan assets at fair value at beginning of year			0		0
U.S. Plans | Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	406		501		501
Quarter activity		(45)	(50)
Benefits earned during the period	0
Interest cost on benefit obligation	4
Actuarial (gain)	(24)
Benefits paid, net of participants’ contributions and government subsidy	(12)
Settlement (gain)	0
Foreign exchange impact and other	0
Projected benefit obligation at period end—Significant Plans	374	406			374
Change in plan assets
Plan assets at fair value at beginning of year	266		319		319
Quarterly activity		(34)	(19)
Actual return on plan assets	(10)
Company contributions, net of reimbursements	6
Benefits paid, net of participants’ contributions and government subsidy	(12)
Settlement gain	0
Foreign exchange impact and other	0
Plan assets at fair value at period end—Significant Plans	250	266			250
Funded status of the Significant Plans	(124)				(124)
Non-U.S. plans | Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year			8,001		8,001
Benefits earned during the period	26			36	90	113
Interest cost on benefit obligation	91			67	243	199
Change in plan assets
Plan assets at fair value at beginning of year			7,614		7,614
Net amount recognized at period end
Benefit asset	793				793
Benefit liability	(429)				(429)
Net amount recognized on the balance sheet—Significant Plans	364				364
Amounts recognized in AOCI at period end(5)
Prior service (expense) benefit	(1)				(1)
Net actuarial (loss) gain	(1,060)				(1,060)
Net amount recognized in equity-pretax	(1,061)				(1,061)
Accumulated benefit obligation at period end—Significant Plans	4,205				4,205
Non-U.S. plans | Pension Plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year			2,071		2,071
Change in plan assets
Plan assets at fair value at beginning of year			1,419		1,419
Non-U.S. plans | Pension Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	4,738		5,930		5,930
Quarter activity		(907)	(285)
Benefits earned during the period	12
Interest cost on benefit obligation	70
Actuarial (gain)	(278)
Benefits paid, net of participants’ contributions and government subsidy	(79)
Settlement (gain)	(2)
Foreign exchange impact and other	(83)
Projected benefit obligation at period end—Significant Plans	4,378	4,738			4,378
Change in plan assets
Plan assets at fair value at beginning of year	5,207		6,195		6,195
Quarterly activity		(762)	(226)
Actual return on plan assets	(310)
Company contributions, net of reimbursements	12
Benefits paid, net of participants’ contributions and government subsidy	(79)
Settlement gain	(2)
Foreign exchange impact and other	(86)
Plan assets at fair value at period end—Significant Plans	4,742	5,207			4,742
Funded status of the Significant Plans	364				364
Non-U.S. plans | Postretirement Benefit Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year			1,169		1,169
Benefits earned during the period	1			2	2	6
Interest cost on benefit obligation	21			$ 25	67	$ 74
Change in plan assets
Plan assets at fair value at beginning of year			1,043		1,043
Net amount recognized at period end
Benefit asset	49				49
Benefit liability	0				0
Net amount recognized on the balance sheet—Significant Plans	49				49
Amounts recognized in AOCI at period end(5)
Prior service (expense) benefit	35				35
Net actuarial (loss) gain	(236)				(236)
Net amount recognized in equity-pretax	(201)				(201)
Accumulated benefit obligation at period end—Significant Plans	723				723
Non-U.S. plans | Postretirement Benefit Plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year			298		298
Change in plan assets
Plan assets at fair value at beginning of year			7		7
Non-U.S. plans | Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	751		871		871
Quarter activity		(49)	(71)
Benefits earned during the period	0
Interest cost on benefit obligation	19
Actuarial (gain)	(33)
Benefits paid, net of participants’ contributions and government subsidy	(14)
Settlement (gain)	0
Foreign exchange impact and other	0
Projected benefit obligation at period end—Significant Plans	723	751			723
Change in plan assets
Plan assets at fair value at beginning of year	828		1,036		1,036
Quarterly activity		(73)	$ (135)
Actual return on plan assets	(42)
Company contributions, net of reimbursements	0
Benefits paid, net of participants’ contributions and government subsidy	(14)
Settlement gain	0
Foreign exchange impact and other	0
Plan assets at fair value at period end—Significant Plans	772	$ 828			772
Funded status of the Significant Plans	49				49
Qualified plans | U.S. Plans | Pension Plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	941				941
Qualified plans | U.S. Plans | Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	(124)				(124)
Qualified plans | Non-U.S. plans | Pension Plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	364				364
Qualified plans | Non-U.S. plans | Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	49				49
Nonqualified plans | U.S. Plans | Pension Plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	(522)				(522)
Nonqualified plans | U.S. Plans | Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	0				0
Nonqualified plans | Non-U.S. plans | Pension Plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	0				0
Nonqualified plans | Non-U.S. plans | Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	$ 0				$ 0