LONG-TERM DEBT - SCHEDULE OF LONG-TERM DEBT (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 265	$ 93
Total	2,701		$ 2,964
Debt Issuance Costs, Net	(16)		(18)
Less current portion	334		319
Long-term debt, less current portion	$ 2,367		$ 2,645
Weighted-average fixed-interest rate	4.30%		4.40%
Weighted-average variable-interest rate	2.60%		2.40%
Fixed rate notes payable due through 2028 [Member]
Debt Instrument [Line Items]
Total	$ 1,024		$ 1,179
Variable rate notes payable due through 2028 [Member]
Debt Instrument [Line Items]
Total	$ 1,693		$ 1,803