Consolidated Statement Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities
Net Earnings (Loss)	$ 827	$ (944)	$ (5,165)
Depreciation, depletion and amortization	833	859	1,488
Impairments		1,396	6,473
Accretion of asset retirement obligation	37	51	45
Deferred income taxes	666	(598)	(2,811)
Unrealized (gain) loss on risk management	(442)	614	331
Unrealized foreign exchange (gain) loss	(291)	(140)	687
Foreign exchange on settlements	24	(68)	358
(Gain) loss on divestitures, net	(404)	(390)	(14)
Other	93	58	38
Net change in other assets and liabilities	(40)	(26)	(11)
Net change in non-cash working capital	(253)	(187)	262
Cash From (Used in) Operating Activities	1,050	625	1,681
Investing Activities
Capital expenditures	(1,796)	(1,132)	(2,232)
Acquisition of Proved, Unproved, and Corporate Property, Plant and Equipment	54	210	70
Proceeds from divestitures	736	1,262	1,908
Net change in investments and other	77	51	(271)
Cash From (Used in) Investing Activities	(1,037)	(29)	(665)
Financing Activities
Net Issuance (repayment) of revolving long-term debt		(650)	(627)
Repayment of long-term debt		(400)	(1,302)
Issuance of common shares		1,129	1,088
Dividends on common shares	(57)	(51)	(152)
Capital lease payments and other financing arrangements	(82)	(66)	(61)
Cash From (Used in) Financing Activities	(139)	(38)	(1,054)
Foreign Exchange Gain (Loss) on Cash and Cash Equivalents Held in Foreign Currency	11	5	(29)
Increase (Decrease) in Cash and Cash Equivalents	(115)	563	(67)
Cash and Cash Equivalents, Beginning of Period	834	271	338
Cash and Cash Equivalents, End of Period	$ 834	$ 271	$ 338