CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues and Other
Sales revenues	$ 3,528	$ 3,414	$ 6,866	$ 6,650
Gains (losses) on divestitures and other, net	86	123	178	142
Total	3,442	3,291	6,660	6,336
Costs and Expenses
Oil and gas operating	310	275	599	551
Oil and gas transportation	222	209	444	405
Exploration	90	94	139	262
General and administrative	368	288	635	566
Merger transaction costs	1,042	0	1,042	0
Depreciation, depletion, and amortization	1,161	1,003	2,242	1,993
Production, property, and other taxes	182	201	381	391
Impairments	0	128	0	147
Other operating expense	8	22	29	162
Total	3,657	2,472	6,041	4,966
Operating Income (Loss)	(215)	819	619	1,370
Other (Income) Expense
Interest expense	249	237	502	465
(Gains) losses on derivatives, net	254	437	569	473
Other (income) expense, net	18	4	24	(8)
Total	521	677	1,093	928
Income (Loss) Before Income Taxes	(736)	142	(474)	442
Income tax expense (benefit)	209	125	375	251
Net Income (Loss)	(945)	17	(849)	191
Net income (loss) attributable to noncontrolling interests	80	(12)	191	41
Net Income (Loss) Attributable to Common Stockholders	$ (1,025)	$ 29	$ (1,040)	$ 150
Per Common Share
Net income (loss) attributable to common stockholders—basic (in usd per share)	$ (2.09)	$ 0.05	$ (2.13)	$ 0.28
Net income (loss) attributable to common stockholders—diluted (in usd per share)	$ (2.09)	$ 0.05	$ (2.13)	$ 0.28
Average Number of Common Shares Outstanding—Basic (in shares)	491	504	491	511
Average Number of Common Shares Outstanding—Diluted (in shares)	491	505	491	512
Commodity Contract and Interest Rate Swap [Member]
Other (Income) Expense
(Gains) losses on derivatives, net	$ 254	$ 436	$ 567	$ 471
Oil sales [Member]
Revenues and Other
Sales revenues	2,470	2,265	4,566	4,392
Natural-gas sales [Member]
Revenues and Other
Sales revenues	205	203	525	450
Natural-gas liquids sales [Member]
Revenues and Other
Sales revenues	216	318	456	610
Gathering, processing, and marketing sales [Member]
Revenues and Other
Sales revenues	465	382	935	742
Costs and Expenses
Gathering, processing, and marketing	$ 274	$ 252	$ 530	$ 489