PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Summary of Net Periodic Benefit Costs) (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2020		Sep. 30, 2019		Sep. 30, 2020		Sep. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 30				$ 30
Net periodic benefit cost (credit) - total	5	[1]	$ 21		24	[2]	$ 60
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	20		17	[3]	55		166	[3]
Interest cost	14		19	[4]	42		610	[4]
Expected return on plan assets	(28)		(35)	[5]	(82)		(954)	[5]
Amortization of prior service credit	(1)		(1)	[6]	(4)		(8)	[6]
Amortization of net (gain) loss	3		(6)	[7]	11		129	[7]
Curtailment/settlement	6		1	[8]	8		(1)	[8]
Net periodic benefit cost (credit) - total	14		(5)		30		(58)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0		0	[3]	0		5	[3]
Interest cost	1		0	[4]	1		52	[4]
Amortization of net (gain) loss	0		0	[7]	0		(6)	[7]
Net periodic benefit cost (credit) - total	1		0		1		51
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (credit) - total	0		0		0		(45)
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (credit) - total	0		0		0		50
Continuing Operations [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost			17				47
Interest cost			19				60
Expected return on plan assets			(35)				(114)
Amortization of prior service credit			(1)				(2)
Amortization of net (gain) loss			(6)				(3)
Curtailment/settlement			1				(1)
Net periodic benefit cost (credit) - total	14		(5)		30		(13)
Continuing Operations [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (credit) - total	$ 1		$ 0		$ 1		$ 1

[1] Included in "Sundry income (expense) - net."

[2] Included in "Sundry income (expense) - net."

[3] The service cost from continuing operations was $17 million and $47 million for the three and nine months ended September 30, 2019, respectively. The activity from OPEBs was immaterial.

[4] The interest cost from continuing operations was $19 million and $60 million for the three and nine months ended September 30, 2019, respectively. The activity from OPEBs was immaterial.

[5] The expected return on plan assets from continuing operations was $35 million and $114 million for the three and nine months ended September 30, 2019, respectively. The activity from OPEBs was immaterial.

[6] The amortization of prior service credit from continuing operations was $1 million and $2 million for the three and nine months ended September 30, 2019, respectively. The activity from OPEBs was immaterial.

[7] The amortization of unrecognized net gain from continuing operations was $6 million and $3 million for the three and nine months ended September 30, 2019, respectively. The activity from OPEBs was immaterial.

[8] Curtailments and settlements from continuing operations resulted in a loss of $1 million for the three months ended September 30, 2019 and a gain of $1 million for the nine months ended September 30, 2019. The activity from OPEBs was immaterial.