RETIREMENT BENEFITS - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Change in accumulated other comprehensive income (loss)
Balance, beginning of period				$ 201,838
Change, net of tax	[1],[2]	$ 312	$ 37	72	$ 119
Balance, end of period		210,195	199,117	210,195	199,117
Consumer loans | Non-U.S. plans | Pension plans
Change in accumulated other comprehensive income (loss)
Curtailment/settlement (gain)					36
Benefit plans
Change in accumulated other comprehensive income (loss)
Balance, beginning of period		(5,995)	(5,770)	(5,755)	(5,852)
Actuarial assumptions changes and plan experience		818	977	703	4,001
Net asset (loss) due to difference between actual and expected returns		(614)	(1,084)	(676)	(4,221)
Net amortization		47	43	135	159
Curtailment/settlement (gain)		5	0	1	(32)
Foreign exchange impact and other		124	60	(95)	193
Change in deferred taxes, net		(68)	41	4	19
Change, net of tax		312	37	72	119
Balance, end of period		$ (5,683)	$ (5,733)	$ (5,683)	$ (5,733)

[1] See Note 8.

[2] See Note 18.