DERIVATIVES (Outstanding Derivative Balances) (Details) - Commodity Risk - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivatives And Hedging Activities [Line Items]
Gross Derivative Assets	$ 47	$ 90
Derivative Asset, Netting	0	0
Cash Collateral	45	98
Total Derivative Balance, Assets	92	188
Current assets – other
Derivatives And Hedging Activities [Line Items]
Gross Derivative Assets	46	44
Derivative Asset, Netting	0	(1)
Cash Collateral	41	89
Total Derivative Balance, Assets	87	132
Other noncurrent assets – other
Derivatives And Hedging Activities [Line Items]
Gross Derivative Assets	170	165
Derivative Asset, Netting	0	0
Cash Collateral	0	0
Total Derivative Balance, Assets	170	165
Current liabilities – other
Derivatives And Hedging Activities [Line Items]
Gross Derivative Liabilities	(29)	(29)
Derivative Liability, Netting	0	1
Cash Collateral	3	7
Total Derivative Balance, Liabilities	(26)	(21)
Noncurrent liabilities – other
Derivatives And Hedging Activities [Line Items]
Gross Derivative Liabilities	(140)	(90)
Derivative Liability, Netting	0	0
Cash Collateral	1	2
Total Derivative Balance, Liabilities	$ (139)	$ (88)