Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net income (loss)	$ 356	$ (4,957)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Discontinued operations	0	4,907
Depreciation, depletion and amortization	590	556
Impairments	8	4
Exploratory dry well costs and unproved property impairments	42	20
Net (gain) loss on disposal of assets	(257)	(1)
Deferred income taxes	(31)	14
Net (gain) loss on derivative instruments	102	(77)
Net settlements of derivative instruments	(59)	(7)
Share-based Compensation	14	14
Equity method investments, net	32	13
Changes in:
Current receivables, changes in	(130)	(1)
Inventories, changes in	(9)	(10)
Current accounts payable and accrued liabilities, changes in	81	(1)
All other operating, net	(90)	27
Net cash provided by operating activities from continuing operations	649	501
Investing activities:
Additions to property, plant and equipment	(662)	(283)
Acquisitions, net of cash acquired	(4)	0
Deposits for acquisitions	0	(180)
Disposal of assets, net of cash transferred to buyer	1,180	0
Equity method investments - return of capital	9	12
All other investing, net	(74)	1
Net cash provided by (used in) investing activities from continuing operations	449	(450)
Financing activities:
Purchases of common stock	(9)	(7)
Dividends paid	(42)	(42)
All other financing, net	2	(1)
Net cash provided by (used in) financing activities	(49)	(50)
Cash flow from discontinued operations:
Operating activities	0	95
Investing activities	0	(9)
Change in cash included in current assets held for sale	0	(86)
Net cash provided by discontinued operations	0	0
Effect of exchange rate on cash and cash equivalents	1	1
Net increase (decrease) in cash and cash equivalents	1,050	2
Cash and cash equivalents at beginning of period	563	2,488
Cash and cash equivalents at end of period	$ 1,613	$ 2,490