PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Defined Benefit Plan Disclosures [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay			5.00%
Automatic Non-Elective Contribution
Defined Benefit Plan Disclosures [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay			4.00%
UNITED STATES
Defined Benefit Plan Disclosures [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer			$ 1,000
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)			1,268
Increase (Decrease) in Obligation, Pension Benefits			(345)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment			19
Pension Plan [Member]
Defined Benefit Plan Disclosures [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 1,230		1,230
Defined Benefit Plan, Plan Assets, Contributions by Employer			1,165
Service cost	95	$ 100	293	$ 298
Interest cost	151	191	444	574
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(434)	(415)	(1,291)	(1,241)
Amortization of prior service credit	(5)	(4)	(15)	(14)
Defined Benefit Plan, Amortization of Gain (Loss)	(198)	(194)	(622)	(578)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	0	0	19	0
Net periodic benefit cost	5	66	34	195
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosures [Line Items]
Service cost	2	2	6	6
Interest cost	6	10	17	29
Defined Benefit Plan, Amortization of Gain (Loss)	2	2	5	7
Net periodic benefit cost	$ 6	$ 10	$ 18	$ 28