Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues and other income:
Sales and other operating revenues, including related party	$ 958	$ 685	$ 1,912	$ 1,251
Marketing revenues	35	76	69	122
Income from equity method investments	51	37	120	51
Net gain (loss) on disposal of assets	6	294	7	234
Other income	9	11	23	15
Total revenues and other income	1,059	1,103	2,131	1,673
Costs and expenses:
Production	176	185	327	372
Marketing, including purchases from related parties	38	75	72	121
Other operating	111	87	200	190
Exploration Expense	30	182	58	206
Depreciation, depletion and amortization	592	512	1,148	1,061
Impairments	0	0	4	1
Taxes other than income	45	35	84	78
General and administrative	93	131	202	282
Total costs and expenses	1,085	1,207	2,095	2,311
Income (loss) from operations	(26)	(104)	36	(638)
Net interest and other	(86)	(88)	(164)	(167)
Income from operations before income taxes	(112)	(192)	(128)	(805)
Provision (benefit) for income taxes	41	(54)	75	(307)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	(153)	(138)	(203)	(498)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	14	(32)	(4,893)	(79)
Net income (loss)	$ (139)	$ (170)	$ (5,096)	$ (577)
Earnings Per Share, Basic [Abstract]
Income (loss) from continuing operations, per basic share	$ (0.18)	$ (0.16)	$ (0.24)	$ (0.63)
Income (loss) from discontinued operations, per basic share	0.02	(0.04)	(5.76)	(0.10)
Net income (loss), per basic share	(0.16)	(0.20)	(6.00)	(0.73)
Earnings Per Share, Diluted [Abstract]
Income (loss) from continuing operations, per diluted share	(0.18)	(0.16)	(0.24)	(0.63)
Income (loss) from discontinued operations, per diluted share	0.02	(0.04)	(5.76)	(0.10)
Net income (loss), per diluted share	(0.16)	(0.20)	(6.00)	(0.73)
Dividends paid, per share	$ 0.05	$ 0.05	$ 0.10	$ 0.10
Weighted average common shares outstanding:
Weighted average common shares outstanding, basic	850	848	850	790
Weighted average common shares outstanding, diluted	850	848	850	790