RETIREMENT BENEFITS - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Change in accumulated other comprehensive income (loss)
Balance, beginning of period				$ 201,838
Change, net of tax	[1],[2]	$ (136)	$ (89)	(240)	$ 82
Balance, end of period		209,422	199,626	209,422	199,626
Benefit plans
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(5,859)	(5,681)	(5,755)	(5,852)
Actuarial assumptions changes and plan experience		154	1,499	(115)	3,024
Net asset (loss) due to difference between actual and expected returns		(245)	(1,675)	(62)	(3,137)
Net amortization		45	52	88	116
Curtailment/settlement (gain)		1	(32)	(4)	(32)
Foreign exchange impact and other		(111)	83	(219)	133
Change in deferred taxes, net		20	(16)	72	(22)
Change, net of tax		(136)	(89)	(240)	82
Balance, end of period		$ (5,995)	$ (5,770)	$ (5,995)	$ (5,770)

[1] See Note 8.

[2] See Note 18.