LONG-TERM DEBT - SCHEDULE OF LONG-TERM DEBT (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Total	$ 2,863		$ 2,964
Less debt issuance costs	(17)		(18)
Less current portion	332		319
Long-term debt, less current portion	$ 2,531		$ 2,645
Weighted-average fixed-interest rate	4.40%		4.40%
Weighted-average variable-interest rate	2.50%		2.40%
Repayments of Long-term Debt	$ 101	$ 36
Fixed-rate notes payable due through 2028 [Member]
Debt Instrument [Line Items]
Total	1,116		$ 1,179
Variable-rate notes payable due through 2028 [Member]
Debt Instrument [Line Items]
Total	$ 1,764		$ 1,803