Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues	$ 3,681	$ 5,696	$ 12,082	$ 16,203
Cost of sales:
Production and delivery	2,893	3,152	8,653	8,971
Depreciation, depletion and amortization	888	945	2,717	2,924
Impairment of oil and gas properties	3,652	308	9,442	308
Total cost of sales	7,433	4,405	20,812	12,203
Selling, general and administrative expenses	124	158	429	457
Mining exploration and research expenses	32	29	101	93
Environmental obligations and shutdown costs	37	18	61	100
Net gain on sales of assets	0	(46)	(39)	(46)
Total costs and expenses	7,626	4,564	21,364	12,807
Operating (loss) income	(3,945)	1,132	(9,282)	3,396
Interest expense, net	(163)	(158)	(458)	(483)
Insurance and other third-party recoveries	0	0	92	0
Net gain on early extinguishment of debt	0	58	0	63
Other (expense) income, net	(40)	23	(88)	48
(Loss) income before income taxes and equity in affiliated companies' net losses	(4,148)	1,055	(9,736)	3,024
Benefit from (provision for) income taxes	360	(349)	1,742	(1,034)
Equity in affiliated companies’ net losses	(2)	(2)	(1)	0
Net (loss) income	(3,790)	704	(7,995)	1,990
Net income attributable to noncontrolling interests	(29)	(142)	(129)	(416)
Preferred dividends attributable to redeemable noncontrolling interest	(11)	(10)	(31)	(30)
Net (loss) income attributable to common stockholders	$ (3,830)	$ 552	$ (8,155)	$ 1,544
Net (loss) income per share attributable to common stockholders:
Basic	$ (3.58)	$ 0.53	$ (7.77)	$ 1.48
Diluted	$ (3.58)	$ 0.53	$ (7.77)	$ 1.47
Weighted-average common shares outstanding:
Basic	1,071	1,039	1,050	1,039
Diluted	1,071	1,046	1,050	1,045
Dividends declared per share of common stock	$ 0.05	$ 0.3125	$ 0.2605	$ 0.9375