Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenues	$ 4,868	$ 3,341
Cost of sales:
Production and delivery	2,808	2,188
Depreciation, depletion and amortization	451	389
Total cost of sales	3,259	2,577
Selling, general and administrative expenses	131	151
Mining exploration and research expenses	21	14
Environmental obligations and shutdown costs	9	25
Net gain on sales of assets	(11)	(23)
Total costs and expenses	3,409	2,744
Operating income	1,459	597
Interest expense, net	(151)	(167)
Other income, net	28	8
Income from continuing operations before income taxes and equity in affiliated companies’ net (losses) earnings	1,336	438
Provision for income taxes	(506)	(174)
Equity in affiliated companies’ net (losses) earnings	(2)	4
Net income from continuing operations	828	268
Net (loss) income from discontinued operations	(11)	38
Net income (loss)	817	306
Net income attributable to noncontrolling interests:
Continuing operations	(125)	(75)
Discontinued operations	0	(3)
Net income attributable to common stockholders	$ 692	$ 228
Basic and diluted net income (loss) per share attributable to common stockholders:
Continuing operations	$ 0.48	$ 0.13
Discontinued operations	(0.01)	0.03
Basic and diluted net income (loss) per share attributable to common stockholders:	$ 0.47	$ 0.16
Basic	1,449	1,446
Diluted	1,458	1,454
Dividends declared per share of common stock	$ 0.05	$ 0