Statement of Consolidated Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 1,676	$ 2,138	$ 807
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, depletion and amortization	2,406	2,317	2,200
(Income) loss from equity investment in HOVENSA L.L.C.	1,073	522	229
Asset impairments	358	532	54
Exploratory dry hole costs	438	237	267
Lease impairment	301	266	231
Stock compensation expense	104	112	128
Gains on asset sales	(446)	(1,208)	0
Provision (benefit) for deferred income taxes	(623)	(495)	(438)
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(243)	(760)	320
(Increase) decrease in inventories	4	(16)	(137)
Increase (decrease) in accounts payable and accrued liabilities	544	1,141	(542)
Increase (decrease) in taxes payable	46	95	(81)
Changes in other assets and liabilities	(654)	(351)	8
Net cash provided by operating activities	4,984	4,530	3,046
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(7,006)	(5,492)	(2,918)
Proceeds from asset sales	490	183	0
Other, net	(50)	50	(6)
Net cash used in investing activities	(6,566)	(5,259)	(2,924)
CASH FLOWS FROM FINANCING ACTIVITIES
Net borrowings (repayments) of debt with maturities of 90 days or less	100	0	(850)
Debt with maturities of greater than 90 days
Borrowings	422	1,278	1,991
Repayments	(100)	(180)	(694)
Cash dividends paid	(136)	(131)	(131)
Noncontrolling interests, net	(49)	(46)	(2)
Employee stock options exercised, including income tax benefits	88	54	18
Net cash provided by financing activities	325	975	332
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(1,257)	246	454
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	1,608	1,362	908
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 351	$ 1,608	$ 1,362