STATEMENT OF CONSOLIDATED CASH FLOWS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	$ 2,001	$ 4,584	$ 3,032
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, and amortization	7,109	4,204	3,083
Asset retirement obligation accretion	232	154	111
Provision for deferred income taxes	677	1,246	952
Other	226	46	190
Changes in operating assets and liabilities:
Receivables	12	(759)	(496)
Inventories	(59)	(37)	35
Drilling advances	(343)	26	(28)
Deferred charges and other	61	27	(141)
Accounts payable	(100)	241	214
Accrued expenses	(1,142)	90	(309)
Deferred credits and noncurrent liabilities	(170)	131	83
NET CASH PROVIDED BY OPERATING ACTIVITIES	8,504	9,953	6,726
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to oil and gas property	(8,781)	(6,414)	(4,407)
Additions to gas gathering, transmission, and processing facilities	(750)	(664)	(515)
Acquisition of Cordillera Energy Partners III, LLC	(2,666)
Acquisition of Yara Pilbara Holdings Pty Limited	(439)
Acquisition of Devon properties			(1,018)
Acquisition of BP properties and facilities			(6,429)
Mariner Energy, Inc. merger			(787)
Acquisition of Mobil North Sea Limited		(1,246)
Acquisitions, other	(252)	(567)	(126)
Proceeds from sale of oil and gas properties	27	422
Other, net	(563)	(176)	(121)
NET CASH USED IN INVESTING ACTIVITIES	(13,424)	(8,645)	(13,403)
CASH FLOWS FROM FINANCING ACTIVITIES:
Commercial paper, credit facility and bank notes, net	549	(925)	(32)
Fixed rate debt borrowings	4,978		2,470
Payments on fixed rate debt	(400)		(1,023)
Proceeds from issuance of common stock			2,258
Proceeds from issuance of mandatory convertible preferred stock			1,227
Dividends paid	(332)	(306)	(226)
Other	(10)	84	89
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	4,785	(1,147)	4,763
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(135)	161	(1,914)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	295	134	2,048
CASH AND CASH EQUIVALENTS AT END OF PERIOD	160	295	134
SUPPLEMENTARY CASH FLOW DATA:
Interest paid, net of capitalized interest	146	156	187
Income taxes paid, net of refunds	$ 2,590	$ 1,686	$ 1,170