PENSION AND POSTRETIREMENT BENEFIT PLANS (Estimated Future Benefit Payments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Pension contributions	$ 396	$ 81	$ 118
Expected future benefit payments, Years 2023-2027	1,600
Defined contribution plan expense	200	$ 200	$ 200
Minimum [Member]
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Expected future benefit payments range	275
Maximum [Member]
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Expected future benefit payments range	300
Pension Plans, Defined Benefit [Member]
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Expected contributions to pension plans	$ 70