RETIREMENT BENEFITS - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in accumulated other comprehensive income (loss)
Beginning of year balance, net of tax		$ 202,672	$ 200,200
Change, net of tax	[1]	97	1,012	$ (55)
End of year balance, net of tax		201,838	202,672	200,200
Benefit plans
Change in accumulated other comprehensive income (loss)
Beginning of year balance, net of tax		(5,852)	(6,864)	(6,809)
Actuarial assumptions changes and plan experience		3,923	963	(1,464)
Net asset gain (loss) due to difference between actual and expected returns		(4,225)	(148)	1,076
Net amortization		198	280	318
Prior service credit (cost)		0	(7)	108
Curtailment/settlement gain (loss)		(37)	11	(8)
Foreign exchange impact and other		172	153	(108)
Change in deferred taxes, net		66	(240)	23
Change, net of tax		97	1,012	(55)
End of year balance, net of tax		$ (5,755)	$ (5,852)	$ (6,864)

[1] See Note 8.