RETIREMENT BENEFITS - Funded Status and Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Change in projected benefit obligation
Actuarial (gain)	$ 1		$ 1	$ 1	$ 1
U.S. plans | Pension plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year		$ 9,640		9,640
Plans measured annually
Service cost	0		0	0	0
Interest cost on benefit obligation	119		123	236	250
Change in plan assets
Plan assets at fair value at beginning of year		10,210		10,210
Net amount recognized at period end
Benefit asset	1,147			1,147
Benefit liability	(488)			(488)
Net amount recognized on the balance sheet—Significant Plans	659			659
Amounts recognized in AOCI at period end(3)
Prior service (expense) benefit	0			0
Net actuarial (loss) gain	(6,251)			(6,251)
Net amount recognized in equity-pretax	(6,251)			(6,251)
Accumulated benefit obligation at period end—Significant Plans	9,147			9,147
U.S. plans | Pension plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year		18		18
Plans measured annually
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	9,378	9,622		9,622
Plans measured annually	(9,147)	(9,378)		(9,147)
Service cost	0
Interest cost on benefit obligation	119
Actuarial (gain)	(118)
Benefits paid, net of participants’ contributions	(232)
Foreign exchange impact and other	0
Projected benefit obligation at period end—Significant Plans	9,147	9,378		9,147
Quarter activity		(244)
Change in plan assets
Plan assets at fair value at beginning of year	10,009	10,210		10,210
Actual return on plan assets	15
Company contributions, net of reimbursements	14
Benefits paid, net of participants’ contributions	(232)
Foreign exchange impact	0
Plan assets at fair value at period end—Significant Plans	9,806	10,009		9,806
Quarterly activity		(201)
Funded status of the Significant Plans	659			659
U.S. plans | Postretirement benefit plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year		343		343
Plans measured annually
Service cost	0		0	0	0
Interest cost on benefit obligation	4		4	8	9
Change in plan assets
Plan assets at fair value at beginning of year		231		231
Net amount recognized at period end
Benefit asset	0			0
Benefit liability	(103)			(103)
Net amount recognized on the balance sheet—Significant Plans	(103)			(103)
Amounts recognized in AOCI at period end(3)
Prior service (expense) benefit	68			68
Net actuarial (loss) gain	111			111
Net amount recognized in equity-pretax	179			179
Accumulated benefit obligation at period end—Significant Plans	320			320
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
Plans measured annually
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	331	343		343
Plans measured annually	(320)	(331)		(320)
Service cost	0
Interest cost on benefit obligation	4
Actuarial (gain)	(3)
Benefits paid, net of participants’ contributions	(12)
Foreign exchange impact and other	0
Projected benefit obligation at period end—Significant Plans	320	331		320
Quarter activity		(12)
Change in plan assets
Plan assets at fair value at beginning of year	231	231		231
Actual return on plan assets	0
Company contributions, net of reimbursements	(2)
Benefits paid, net of participants’ contributions	(12)
Foreign exchange impact	0
Plan assets at fair value at period end—Significant Plans	217	231		217
Quarterly activity		0
Funded status of the Significant Plans	(103)			(103)
Non-U.S. plans | Pension plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year		7,030		7,030
Plans measured annually
Service cost	30		30	59	58
Interest cost on benefit obligation	109		102	218	200
Change in plan assets
Plan assets at fair value at beginning of year		6,426		6,426
Net amount recognized at period end
Benefit asset	743			743
Benefit liability	(817)			(817)
Net amount recognized on the balance sheet—Significant Plans	(74)			(74)
Amounts recognized in AOCI at period end(3)
Prior service (expense) benefit	(6)			(6)
Net actuarial (loss) gain	(1,503)			(1,503)
Net amount recognized in equity-pretax	(1,509)			(1,509)
Accumulated benefit obligation at period end—Significant Plans	4,721			4,721
Non-U.S. plans | Pension plans | Other than Significant Plans Measured Annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year		1,663		1,663
Plans measured annually
Change in plan assets
Plan assets at fair value at beginning of year		(1,198)		(1,198)
Non-U.S. plans | Pension plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	5,291	5,367		5,367
Plans measured annually	(4,915)	(5,291)		(4,915)
Service cost	12
Interest cost on benefit obligation	90
Actuarial (gain)	(116)
Benefits paid, net of participants’ contributions	(81)
Foreign exchange impact and other	(281)
Projected benefit obligation at period end—Significant Plans	4,915	5,291		4,915
Quarter activity		(76)
Change in plan assets
Plan assets at fair value at beginning of year	5,116	5,228		5,228
Actual return on plan assets	1
Company contributions, net of reimbursements	8
Benefits paid, net of participants’ contributions	(81)
Foreign exchange impact	(203)
Plan assets at fair value at period end—Significant Plans	4,841	5,116		4,841
Quarterly activity		(112)
Funded status of the Significant Plans	(74)			(74)
Non-U.S. plans | Postretirement benefit plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year		1,208		1,208
Plans measured annually
Service cost	1		0	1	1
Interest cost on benefit obligation	28		$ 27	57	$ 52
Change in plan assets
Plan assets at fair value at beginning of year		970		970
Net amount recognized at period end
Benefit asset	0			0
Benefit liability	(5)			(5)
Net amount recognized on the balance sheet—Significant Plans	(5)			(5)
Amounts recognized in AOCI at period end(3)
Prior service (expense) benefit	27			27
Net actuarial (loss) gain	(272)			(272)
Net amount recognized in equity-pretax	(245)			(245)
Accumulated benefit obligation at period end—Significant Plans	870			870
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		219		219
Plans measured annually
Change in plan assets
Plan assets at fair value at beginning of year		(9)		(9)
Non-U.S. plans | Postretirement benefit plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	986	989		989
Plans measured annually	(870)	(986)		(870)
Service cost	0
Interest cost on benefit obligation	25
Actuarial (gain)	(29)
Benefits paid, net of participants’ contributions	(20)
Foreign exchange impact and other	(92)
Projected benefit obligation at period end—Significant Plans	870	986		870
Quarter activity		(3)
Change in plan assets
Plan assets at fair value at beginning of year	953	961		961
Actual return on plan assets	22
Company contributions, net of reimbursements	0
Benefits paid, net of participants’ contributions	(20)
Foreign exchange impact	(90)
Plan assets at fair value at period end—Significant Plans	865	953		865
Quarterly activity		$ (8)
Funded status of the Significant Plans	(5)			(5)
Qualified plans | U.S. plans | Pension plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	1,147			1,147
Qualified plans | U.S. plans | Postretirement benefit plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	(103)			(103)
Qualified plans | Non-U.S. plans | Pension plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	(74)			(74)
Qualified plans | Non-U.S. plans | Postretirement benefit plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	(5)			(5)
Nonqualified plans | U.S. plans | Pension plans | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the Significant Plans	(488)			(488)
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