PENSION AND POSTRETIREMENT BENEFIT PLANS (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 63	$ 71	$ 396
Total net periodic benefit cost/(credit)	1,599	(27)	(1)
Pension Plans, Defined Benefit [Member]
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	63	71
Service cost - benefits earned during the year	26	26	25
Interest cost on projected benefit obligation	115	193	188
Expected return on plan assets	(200)	(386)	(411)
Amortization of prior service costs	(4)	(4)	(4)
Amortization of net actuarial (gain)/loss	59	74	82
Curtailments	1,640	121	159
Special termination benefits	0	0	3
Total net periodic benefit cost/(credit)	$ 1,636	$ 24	$ 42