PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Fair Value Measurement of Level 3 Pension Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 28,200	$ 26,400
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28,167	26,406	$ 24,908
Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	27	40
Plan Assets Sold		(11)
Plan Assets Still Held	(10)	6
Purchases, sales and settlements, net	(5)	(12)
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Assets Transferred into (out of) Level 3		4
Equity securities | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,676	9,120
Equity securities | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	10	27
Plan Assets Sold		0
Plan Assets Still Held	1	(1)
Purchases, sales and settlements, net	(5)	(19)
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Assets Transferred into (out of) Level 3		3
Fixed Income Securities | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,904	9,071
Fixed Income Securities | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	2	2
Plan Assets Sold		0
Plan Assets Still Held	0	0
Purchases, sales and settlements, net	(1)	(1)
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Assets Transferred into (out of) Level 3		1
Alternative Investments | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	147	167
Alternative Investments | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	13	11
Plan Assets Sold		(11)
Plan Assets Still Held	(11)	8
Purchases, sales and settlements, net	3	5
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Assets Transferred into (out of) Level 3		0
Other Investments | Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,068	472
Other Investments | Defined Benefit Pension Plans | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	2	$ 0
Plan Assets Sold		0
Plan Assets Still Held	0	(1)
Purchases, sales and settlements, net	$ (2)	3
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Assets Transferred into (out of) Level 3		$ 0