POSTRETIREMENT BENEFIT PLANS - Effect on Operations of Pension Plans (Details) - Principal pension - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	$ 14	$ 16	$ 47	$ 53
Prior service cost amortization	(2)	1	(7)	5
Expected return on plan assets	(375)	(392)	(1,125)	(1,360)
Interest cost on benefit obligations	325	317	976	1,085
Net actuarial gain amortization	(126)	(105)	(379)	(362)
Net periodic expense (income)	(164)	(163)	(488)	(579)
Discontinued operations
Defined Benefit Plan Disclosure [Line Items]
Net periodic expense (income)	0	0	0	(88)
Continuing operations
Defined Benefit Plan Disclosure [Line Items]
Net periodic expense (income)	$ (164)	$ (163)	$ (488)	$ (491)