Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues and other income:
Revenues from contracts with customers	$ 1,447	$ 902	$ 2,984	$ 1,775
Net gain (loss) on commodity derivatives	(152)	56	(254)	137
Marketing revenues	0	35	0	69
Income from equity method investments	60	51	97	120
Net gain (loss) on disposal of assets	50	6	307	7
Other income	12	9	16	23
Total revenues and other income	1,417	1,059	3,150	2,131
Costs and expenses:
Production	205	178	422	331
Marketing, including purchases from related parties	0	38	0	72
Shipping, handling and other operating	126	111	256	200
Exploration	65	30	117	58
Depreciation, depletion and amortization	612	592	1,202	1,148
Impairments	34	0	42	4
Taxes other than income	65	45	129	84
General and administrative	105	90	205	187
Total costs and expenses	1,212	1,084	2,373	2,084
Income (loss) from operations	205	(25)	777	47
Net interest and other	(65)	(86)	(110)	(164)
Other net periodic benefit costs	0	(1)	(3)	(11)
Income (loss) from continuing operations before income taxes	140	(112)	664	(128)
Provision (benefit) for income taxes	44	41	212	75
Income (loss) from continuing operations	96	(153)	452	(203)
Income (loss) from discontinued operations	0	14	0	(4,893)
Net income (loss)	$ 96	$ (139)	$ 452	$ (5,096)
Per basic share:
Income (loss) from continuing operations, per basic share	$ 0.11	$ (0.18)	$ 0.53	$ (0.24)
Income (loss) from discontinued operations, per basic share	0.00	0.02	0.00	(5.76)
Net income (loss), per basic share	0.11	(0.16)	0.53	(6.00)
Per diluted share:
Income (loss) from continuing operations, per diluted share	0.11	(0.18)	0.53	(0.24)
Income (loss) from discontinued operations, per diluted share	0.00	0.02	0.00	(5.76)
Net income (loss), per diluted share	0.11	(0.16)	0.53	(6.00)
Dividends paid, per share	$ 0.05	$ 0.05	$ 0.10	$ 0.10
Weighted average common shares outstanding:
Weighted average common shares outstanding, basic	854	850	853	850
Weighted average common shares outstanding, diluted	855	850	854	850