Statement of Consolidated Operations (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
REVENUES AND OTHER:
Oil and gas production revenues	$ 3,956	$ 4,355	$ 8,413	$ 8,233
Other	16	(17)	95	30
Total revenues and other	3,972	4,338	8,508	8,263
Depreciation, depletion and amortization [Abstract]
Recurring	1,284	1,033	2,503	1,939
Additional	648	26	1,169	26
Asset retirement obligation accretion	57	38	112	75
Lease operating expenses	704	662	1,377	1,285
Gathering and transportation	72	73	149	149
Taxes other than income	203	255	460	419
General and administrative	132	103	260	215
Merger, acquisitions & transition	16	6	22	11
Financing costs, net	45	41	85	86
Total operating expenses	3,161	2,207	6,137	4,205
INCOME (LOSS) BEFORE INCOME TAXES	811	2,131	2,371	4,058
Current income tax provision	460	576	1,185	1,219
Deferred income tax provision (benefit)	(5)	296	33	446
NET INCOME	356	1,259	1,153	2,393
Preferred stock dividends	19	19	38	38
INCOME ATTRIBUTABLE TO COMMON STOCK	$ 337	$ 1,240	$ 1,115	$ 2,355
NET INCOME PER COMMON SHARE:
Basic	$ 0.87	$ 3.23	$ 2.88	$ 6.14
Diluted	$ 0.86	$ 3.17	$ 2.86	$ 6.03
WEIGHTED-AVERAGE NUMBER OF COMMON SHARES OUTSTANDING:
Basic	389	384	387	383
Diluted	390	397	403	397
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.17	$ 0.15	$ 0.34	$ 0.30