DERIVATIVES (Outstanding Derivative Balances) (Details) - Commodity Risk - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Derivatives And Hedging Activities [Line Items]
Gross Derivative Assets	$ 116	$ 90
Derivative Asset, Netting	0	0
Cash Collateral	51	98
Total Derivative Balance, Assets	167	188
Current assets – other
Derivatives And Hedging Activities [Line Items]
Gross Derivative Assets	47	44
Derivative Asset, Netting	(4)	(1)
Cash Collateral	48	89
Total Derivative Balance, Assets	91	132
Other noncurrent assets – other
Derivatives And Hedging Activities [Line Items]
Gross Derivative Assets	161	165
Derivative Asset, Netting	0	0
Cash Collateral	0	0
Total Derivative Balance, Assets	161	165
Current liabilities – other
Derivatives And Hedging Activities [Line Items]
Gross Derivative Liabilities	(25)	(29)
Derivative Liability, Netting	4	1
Cash Collateral	3	7
Total Derivative Balance, Liabilities	(18)	(21)
Noncurrent liabilities – other
Derivatives And Hedging Activities [Line Items]
Gross Derivative Liabilities	(67)	(90)
Derivative Liability, Netting	0	0
Cash Collateral	0	2
Total Derivative Balance, Liabilities	$ (67)	$ (88)