Accrued Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Accrued Liabilities [Line Items]
Accrued liabilities	$ 434	$ 498
Revenue payable
Accrued Liabilities [Line Items]
Accrued liabilities	210	196
Accrued capital costs
Accrued Liabilities [Line Items]
Accrued liabilities	96	92
Accrued lease operating expenses
Accrued Liabilities [Line Items]
Accrued liabilities	31	37
Employee incentive expense
Accrued Liabilities [Line Items]
Accrued liabilities	16	48
Accrued interest on debt
Accrued Liabilities [Line Items]
Accrued liabilities	32	67
Taxes payable
Accrued Liabilities [Line Items]
Accrued liabilities	13	15
Other
Accrued Liabilities [Line Items]
Accrued liabilities	$ 36	$ 43