RETIREMENT BENEFITS - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Change in accumulated other comprehensive income (loss)
Balance, beginning of period				$ 206,251
Change, net of tax	[1],[2]	$ 179	$ (136)	256	$ (240)
Balance, end of period		209,144	209,422	209,144	209,422
Benefit plans
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(5,973)	(5,859)	(6,050)	(5,755)
Actuarial assumptions changes and plan experience		256	154	536	(115)
Net (loss) due to difference between actual and expected returns		(205)	(245)	(476)	(62)
Net amortization		61	45	125	88
Curtailment/settlement (gain)		4	1	4	(4)
Foreign exchange impact and other		133	(111)	128	(219)
Change in deferred taxes, net		(70)	20	(61)	72
Change, net of tax		179	(136)	256	(240)
Balance, end of period		$ (5,794)	$ (5,995)	$ (5,794)	$ (5,995)

[1] See Note 8.

[2] See Note 19.