Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOW FROM OPERATING ACTIVITIES
Net income (loss)	$ 1,311	$ (574)	$ (7,829)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Income from discontinued operations		(428)	(317)
Depreciation, depletion and amortization of assets	4,002	4,268	4,544
Deferred income tax benefit	(719)	(517)	(1,372)
Other noncash charges to income	222	121	159
Asset impairments and related items	545	665	9,684
Gain on sale of equity investments and other assets	(667)	(202)	(101)
Undistributed earnings from equity investments	(68)	3	6
Dry hole expenses	51	33	10
Changes in operating assets and liabilities:
Decrease (increase) in receivables	(158)	(1,091)	1,431
Decrease (increase) in inventories	(349)	17	(24)
Decrease in other current assets	39	65	33
(Decrease) increase in accounts payable and accrued liabilities	43	603	(1,989)
(Decrease) increase in current domestic and foreign income taxes	64	17	(331)
Other operating, net	680	(461)	(650)
Operating cash flow from continuing operations	4,996	2,519	3,254
Operating cash flow from discontinued operations, net of taxes		864	97
Net cash provided by operating activities	4,996	3,383	3,351
CASH FLOW FROM INVESTING ACTIVITIES
Capital expenditures	(3,599)	(2,717)	(5,272)
Change in capital accrual	122	(114)	(592)
Payments for purchases of assets and businesses	(1,064)	(2,044)	(109)
Sales of equity investments and assets, net	1,403	302	819
Other, net	(76)	(169)	(269)
Net cash used by investing activities	(3,214)	(4,742)	(5,423)
CASH FLOW FROM FINANCING ACTIVITIES
Proceeds from long-term debt		4,203	1,478
Payments of long-term debt		(2,710)
Change in restricted cash		1,193	2,826
Proceeds from issuance of common stock	28	36	37
Purchases of treasury stock	(25)	(22)	(593)
Cash dividends paid	(2,346)	(2,309)	(2,264)
Net cash provided (used) by financing activities	(2,343)	391	1,484
Decrease in cash and cash equivalents	(561)	(968)	(588)
Cash and cash equivalents - beginning of year	2,233	3,201	3,789
Cash and cash equivalents - end of year	$ 1,672	$ 2,233	$ 3,201