Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
	Jun. 27, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Revenues		$ 5,168	$ 3,711	$ 10,036	$ 7,052
Cost of sales:
Production and delivery		2,915	2,480	5,723	4,668
Depreciation, depletion and amortization		442	450	893	839
Total cost of sales		3,357	2,930	6,616	5,507
Selling, general and administrative expenses		109	107	240	258
Mining exploration and research expenses		24	19	45	33
Environmental obligations and shutdown costs		59	(21)	68	4
Net gain on sales of assets		(45)	(10)	(56)	(33)
Total costs and expenses		3,504	3,025	6,913	5,769
Operating income		1,664	686	3,123	1,283
Interest expense, net		(142)	(162)	(293)	(329)
Net gain (loss) on early extinguishment of debt		9	(4)	8	(3)
Other income (expense), net		20	(7)	49	0
Income from continuing operations before income taxes and equity in affiliated companies’ net earnings (losses)		1,551	513	2,887	951
Provision for income taxes		(515)	(186)	(1,021)	(360)
Equity in affiliated companies’ net earnings (losses)		3	(1)	1	3
Net income from continuing operations		1,039	326	1,867	594
Net (loss) income from discontinued operations		(4)	9	(15)	47
Net income (loss)		1,035	335	1,852	641
Net income attributable to noncontrolling interests:
Continuing operations		(166)	(66)	(291)	(141)
Net income from discontinued operations attributable to noncontrolling interests		0	(1)	0	(4)
Net income attributable to common stockholders		$ 869	$ 268	$ 1,561	$ 496
Earnings Per Share, Basic [Abstract]
Income (Loss) from Continuing Operations, Per Basic Share		$ 0.60	$ 0.18	$ 1.08	$ 0.31
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share		0.00	0.00	(0.01)	0.03
Earnings Per Share, Basic		0.60	0.18	1.07	0.34
Earnings Per Share, Diluted [Abstract]
Income (Loss) from Continuing Operations, Per Diluted Share		0.59	0.18	1.08	0.31
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share		0.00	0.00	(0.01)	0.03
Earnings Per Share, Diluted		$ 0.59	$ 0.18	$ 1.07	$ 0.34
Basic weighted-average shares of common stock outstanding		1,449	1,447	1,449	1,447
Diluted weighted-average shares of common shares outstanding		1,458	1,453	1,458	1,453
Dividends declared per share of common stock	$ 0.05	$ 0.05	$ 0	$ 0.10	$ 0