CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities
Net income (loss)		$ (211)		$ (2,808)	$ (6,812)
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Depreciation, depletion, and amortization		4,279		4,301	4,603
Deferred income taxes		(2,169)		(1,238)	(3,152)
Dry hole expense and impairments of unproved properties		2,221		613	2,267
Impairments		408		227	5,075
(Gains) losses on divestitures, net	[1]	(674)	[2]	757	1,022
Loss on early extinguishment of debt		2		155	0
Total (gains) losses on derivatives, net		131		292	(100)
Operating portion of net cash received (paid) in settlement of derivative instruments		25		267	335
Other		303		342	320
Changes in assets and liabilities
(Increase) decrease in accounts receivable		(147)		677	(2)
Increase (decrease) in accounts payable and other current liabilities		(32)		(443)	(697)
Other items, net		(127)		(142)	474
Net cash provided by (used in) operating activities		4,009		3,000	(1,877)
Cash Flows from Investing Activities
Additions to properties and equipment		(5,031)		(3,505)	(6,067)
Acquisition of businesses		25		(1,740)	(3)
Divestitures of properties and equipment and other assets		4,008		2,356	1,415
Other, net		(30)		127	(116)
Net cash provided by (used in) investing activities		(1,028)		(2,762)	(4,771)
Cash Flows from Financing Activities
Borrowings, net of issuance costs		369		6,042	4,632
Repayments of debt		(58)		(6,832)	(4,033)
Financing portion of net cash received (paid) for derivative instruments		(165)		(333)	(35)
Increase (decrease) in outstanding checks		(43)		(103)	(23)
Dividends paid		(111)		(105)	(553)
Repurchase of common stock		(1,092)		(38)	(55)
Issuance of common stock		0		2,188	34
Distributions to noncontrolling interest owners		(445)		(362)	(282)
Proceeds from conveyance of future hard-minerals royalty revenues, net of transaction costs		0		413	0
Payments of future hard-minerals royalty revenues conveyed		(50)		(25)	0
Other financing activities		(18)		0	0
Net cash provided by (used in) financing activities		(1,613)		2,008	220
Effect of Exchange Rate Changes on Cash		1		(1)	(2)
Net Increase (Decrease) in Cash and Cash Equivalents		1,369		2,245	(6,430)
Cash and Cash Equivalents at Beginning of Period		3,184		939	7,369
Cash and Cash Equivalents at End of Period		4,553		3,184	939
Subsidiary Equity Transactions [Member]
Cash Flows from Financing Activities
Issuance of units		0		1,163	187
Equity Component of 7.5% Tangible Equity Units [Member]
Cash Flows from Financing Activities
Issuance of units		0		0	348
Tronox Litigation [Member] | Judicial Ruling [Member]
Changes in assets and liabilities
Tronox-related contingent liability		$ 0		$ 0	$ (5,210)

[1] Includes goodwill allocated to divestitures of $209 million in 2017, $397 million in 2016, and $184 million in 2015.

[2] Includes the $126 million gain related to the property exchange discussed above.