RETIREMENT BENEFITS - Fair Value Disclosure (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
U.S.
Defined Benefit Plan Disclosure
Total net assets	$ 10,441	$ 10,398
U.S. | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	7,869	7,797
U.S. | Level 1
Defined Benefit Plan Disclosure
Total net assets	1,557	1,782
U.S. | Level 2
Defined Benefit Plan Disclosure
Total net assets	6,307	6,008
U.S. | Level 3
Defined Benefit Plan Disclosure
Total net assets	5	7	$ 29
U.S. | Total investments | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	7,381	7,250
U.S. | Total investments | Level 1
Defined Benefit Plan Disclosure
Total net assets	1,549	1,753
U.S. | Total investments | Level 2
Defined Benefit Plan Disclosure
Total net assets	5,827	5,490
U.S. | Total investments | Level 3
Defined Benefit Plan Disclosure
Total net assets	5	7
U.S. | U.S. equities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	262	233
U.S. | U.S. equities | Level 1
Defined Benefit Plan Disclosure
Total net assets	262	233
U.S. | U.S. equities | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | U.S. equities | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Non-U.S. equities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	315	346
U.S. | Non-U.S. equities | Level 1
Defined Benefit Plan Disclosure
Total net assets	315	346
U.S. | Non-U.S. equities | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Non-U.S. equities | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Mutual funds and other registered investment companies | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	244	243
U.S. | Mutual funds and other registered investment companies | Level 1
Defined Benefit Plan Disclosure
Total net assets	244	243
U.S. | Mutual funds and other registered investment companies | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Mutual funds and other registered investment companies | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Commingled funds | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	622	818
U.S. | Commingled funds | Level 1
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Commingled funds | Level 2
Defined Benefit Plan Disclosure
Total net assets	622	818
U.S. | Commingled funds | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Debt securities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	5,731	5,567
U.S. | Debt securities | Level 1
Defined Benefit Plan Disclosure
Total net assets	690	929
U.S. | Debt securities | Level 2
Defined Benefit Plan Disclosure
Total net assets	5,041	4,638
U.S. | Debt securities | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Annuity contracts | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	3	3
U.S. | Annuity contracts | Level 1
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Annuity contracts | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Annuity contracts | Level 3
Defined Benefit Plan Disclosure
Total net assets	3	3	4
U.S. | Derivatives | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	202	36
U.S. | Derivatives | Level 1
Defined Benefit Plan Disclosure
Total net assets	38	2
U.S. | Derivatives | Level 2
Defined Benefit Plan Disclosure
Total net assets	164	34
U.S. | Derivatives | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Other investments | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	2	4
U.S. | Other investments | Level 1
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Other investments | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Other investments | Level 3
Defined Benefit Plan Disclosure
Total net assets	2	4	25
U.S. | Cash and short-term investments | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	662	602
U.S. | Cash and short-term investments | Level 1
Defined Benefit Plan Disclosure
Total net assets	11	39
U.S. | Cash and short-term investments | Level 2
Defined Benefit Plan Disclosure
Total net assets	651	563
U.S. | Cash and short-term investments | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Other investment liabilities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	(174)	(55)
U.S. | Other investment liabilities | Level 1
Defined Benefit Plan Disclosure
Total net assets	(3)	(10)
U.S. | Other investment liabilities | Level 2
Defined Benefit Plan Disclosure
Total net assets	(171)	(45)
U.S. | Other investment liabilities | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
U.S. | Other investment liabilities redeemed at NAV | Net Asset Value
Defined Benefit Plan Disclosure
Total net assets	(127)
U.S. | Other investment receivables redeemed at NAV | Net Asset Value
Defined Benefit Plan Disclosure
Total net assets		21
U.S. | Securities | Net Asset Value
Defined Benefit Plan Disclosure
Total net assets	2,699	2,580
Non-U.S.
Defined Benefit Plan Disclosure
Total net assets	7,396	6,941
Non-U.S. | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	7,380	6,925
Non-U.S. | Level 1
Defined Benefit Plan Disclosure
Total net assets	6,276	6,296
Non-U.S. | Level 2
Defined Benefit Plan Disclosure
Total net assets	869	367
Non-U.S. | Level 3
Defined Benefit Plan Disclosure
Total net assets	235	262	322
Non-U.S. | Total investments | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	8,891	9,286
Non-U.S. | Total investments | Level 1
Defined Benefit Plan Disclosure
Total net assets	6,193	6,227
Non-U.S. | Total investments | Level 2
Defined Benefit Plan Disclosure
Total net assets	2,463	2,797
Non-U.S. | Total investments | Level 3
Defined Benefit Plan Disclosure
Total net assets	235	262
Non-U.S. | U.S. equities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	133	131
Non-U.S. | U.S. equities | Level 1
Defined Benefit Plan Disclosure
Total net assets	133	121
Non-U.S. | U.S. equities | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	10
Non-U.S. | U.S. equities | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Non-U.S. equities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	722	737
Non-U.S. | Non-U.S. equities | Level 1
Defined Benefit Plan Disclosure
Total net assets	722	718
Non-U.S. | Non-U.S. equities | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	19
Non-U.S. | Non-U.S. equities | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Mutual funds and other registered investment companies | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	3,016	2,712
Non-U.S. | Mutual funds and other registered investment companies | Level 1
Defined Benefit Plan Disclosure
Total net assets	2,706	2,416
Non-U.S. | Mutual funds and other registered investment companies | Level 2
Defined Benefit Plan Disclosure
Total net assets	310	296
Non-U.S. | Mutual funds and other registered investment companies | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Commingled funds | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	12	13
Non-U.S. | Commingled funds | Level 1
Defined Benefit Plan Disclosure
Total net assets	12	13
Non-U.S. | Commingled funds | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Commingled funds | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Debt securities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	3,636	3,939
Non-U.S. | Debt securities | Level 1
Defined Benefit Plan Disclosure
Total net assets	2,620	2,959
Non-U.S. | Debt securities | Level 2
Defined Benefit Plan Disclosure
Total net assets	1,016	980
Non-U.S. | Debt securities | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Real estate | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	2	4
Non-U.S. | Real estate | Level 1
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Real estate | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	2
Non-U.S. | Real estate | Level 3
Defined Benefit Plan Disclosure
Total net assets	2	2	2
Non-U.S. | Annuity contracts | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	2	2
Non-U.S. | Annuity contracts | Level 1
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Annuity contracts | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Annuity contracts | Level 3
Defined Benefit Plan Disclosure
Total net assets	2	2	2
Non-U.S. | Derivatives | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	1,137	1,490
Non-U.S. | Derivatives | Level 1
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Derivatives | Level 2
Defined Benefit Plan Disclosure
Total net assets	1,137	1,490
Non-U.S. | Derivatives | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Other investments | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	231	258
Non-U.S. | Other investments | Level 1
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Other investments | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Other investments | Level 3
Defined Benefit Plan Disclosure
Total net assets	231	258	318
Non-U.S. | Cash and short-term investments | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	83	75
Non-U.S. | Cash and short-term investments | Level 1
Defined Benefit Plan Disclosure
Total net assets	83	69
Non-U.S. | Cash and short-term investments | Level 2
Defined Benefit Plan Disclosure
Total net assets	0	6
Non-U.S. | Cash and short-term investments | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Other investment liabilities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan Disclosure
Total net assets	(1,594)	(2,436)
Non-U.S. | Other investment liabilities | Level 1
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Other investment liabilities | Level 2
Defined Benefit Plan Disclosure
Total net assets	(1,594)	(2,436)
Non-U.S. | Other investment liabilities | Level 3
Defined Benefit Plan Disclosure
Total net assets	0	0
Non-U.S. | Securities | Net Asset Value
Defined Benefit Plan Disclosure
Total net assets	16	16
Pension Plans | U.S.
Defined Benefit Plan Disclosure
Total net assets	$ 10,210	$ 10,145	12,977
Allocable interest (as a percent)	98.00%	98.00%
Pension Plans | Non-U.S.
Defined Benefit Plan Disclosure
Total net assets	$ 6,426	$ 6,086	7,614
Postretirement Benefit Plans | U.S.
Defined Benefit Plan Disclosure
Total net assets	$ 231	$ 253	319
Allocable interest (as a percent)	2.00%	2.00%
Postretirement Benefit Plans | Non-U.S.
Defined Benefit Plan Disclosure
Total net assets	$ 970	$ 855	$ 1,043