RETIREMENT BENEFITS - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Change in accumulated other comprehensive income (loss)
Balance, beginning of period				$ 202,672
Change, net of tax	[1]	$ 37	$ 135	119	$ 936
Balance, end of period		199,117	201,610	199,117	201,610
Benefit plans
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(5,770)	(6,063)	(5,852)	(6,864)
Actuarial assumptions changes and plan experience		977		4,001
Net asset (loss) due to difference between actual and expected returns		(1,084)		(4,221)
Net amortization		43		159
Curtailment/settlement (gain)		0		(32)
Foreign exchange impact and other		60		193
Change in deferred taxes, net		41		19
Change, net of tax		37		119
Balance, end of period		$ (5,733)	$ (5,928)	$ (5,733)	$ (5,928)

[1] See Note 17.