PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Summary of Net Periodic Benefit Costs) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020		Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 45				$ 45
Net periodic benefit cost (credit) - total	8	[1]	$ 18		19	[2]	$ 39
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	17		18	[3]	35		149	[3]
Interest cost	14		144	[4]	28		591	[4]
Expected return on plan assets	(26)		(206)	[5]	(54)		(919)	[5]
Amortization of prior service credit	(2)		(1)	[6]	(3)		(7)	[6]
Amortization of net (gain) loss	4		2	[7]	8		135	[7]
Curtailment/settlement	2		(2)	[8]	2		(2)	[8]
Net periodic benefit cost (credit) - total	9		(45)		16		(53)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0		1	[3]	0		5	[3]
Interest cost	0		15	[4]	0		52	[4]
Amortization of net (gain) loss	0		0	[7]	0		(6)	[7]
Net periodic benefit cost (credit) - total	0		16		0		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		(41)		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		16		0		50
Continuing Operations [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost			14				30
Interest cost			20				41
Expected return on plan assets			(36)				(79)
Amortization of prior service credit							(1)
Amortization of net (gain) loss			1				3
Curtailment/settlement							(2)
Net periodic benefit cost (credit) - total	9		(4)		16		(8)
Continuing Operations [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (credit) - total	$ 0		$ 0		$ 0		$ 1

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

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

[3] The service cost from continuing operations was $14 million and $30 million for the three and six months ended June 30, 2019, respectively. The activity from OPEBs was immaterial.

[4] The interest cost from continuing operations was $20 million and $41 million for the three and six months ended June 30, 2019, respectively. The activity from OPEBs was immaterial.

[5] The expected return on plan assets from continuing operations was $36 million and $79 million for the three and six months ended June 30, 2019, respectively. The activity from OPEBs was immaterial.

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

[7] The amortization of unrecognized net loss from continuing operations was $1 million and $3 million for the three and six months ended June 30, 2019, respectively. The activity from OPEBs was immaterial.

[8] The curtailment and settlement gains from continuing operations were $2 million for the three and six months ended June 30, 2019. The activity from OPEBs was immaterial.