CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenues	$ 14,198	$ 14,402	$ 18,628
Cost of sales:
Production and delivery	10,031	11,534	11,708
Cost, Depreciation, Amortization and Depletion	1,528	1,412	1,754
Total cost of sales	11,655	13,125	13,466
Selling, general and administrative expenses	370	394	422
Exploration Expense	50	104	105
Environmental obligations and shutdown costs	159	105	89
Net gain on sales of assets	(473)	(417)	(208)
Total costs and expenses	11,761	13,311	13,874
Operating income	2,437	1,091	4,754
Interest expense, net	(598)	(620)	(945)
Net (loss) gain on early extinguishment of debt	(101)	(27)	7
Other income (expense), net	59	(138)	76
Income from continuing operations before income taxes and equity in affiliated companies’ net earnings	1,797	306	3,892
Provision for (benefit from) income taxes	(944)	(510)	(991)
Equity in affiliated companies’ net earnings	12	12	8
Net income (loss) from continuing operations	865	(192)	2,909
Net income (loss) from discontinued operations	0	3	(15)
Net income (loss)	865	(189)	2,894
Net income from continuing operations attributable to noncontrolling interests	(266)	(50)	(292)
Net income (loss) attributable to common stockholders	$ 599	$ (239)	$ 2,602
Basic net income (loss) per share attributable to common stockholders:
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.41	$ (0.17)	$ 1.80
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0	0	(0.01)
Earnings per share, basic (in dollars per share)	0.41	(0.17)	1.79
Diluted net income (loss) per share attributable to common stockholders:
Income (Loss) from Continuing Operations, Per Diluted Share	0.41	(0.17)	1.79
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share			(0.01)
Earnings Per Share, Diluted	$ 0.41	$ (0.17)	$ 1.78
Weighted Average Number of Shares Outstanding, Basic	1,453	1,451	1,449
Weighted Average Number of Shares Outstanding, Diluted	1,461	1,451	1,458
Dividends declared per share of common stock (in dollars per share)	$ 0	$ 0.20	$ 0.20
Direct Operating Costs	$ 10,031	$ 11,534	$ 11,708
Inventory Adjustment	$ 96	$ 179	$ 4
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic and Diluted Share	$ 0	$ 0	$ (0.01)