POSTRETIREMENT BENEFIT PLANS - Effect on Operations of Pension Plans (Details) - Principal pension plans - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	$ 48	$ 57	$ 146	$ 179
Prior service cost amortization	1	8	4	22
Expected return on plan assets	(785)	(763)	(2,356)	(2,288)
Interest cost on benefit obligations	518	488	1,551	1,464
Net actuarial loss amortization	355	871	1,067	2,613
Benefit plans cost	$ 137	$ 661	$ 412	$ 1,990