Statement of Consolidated Operations (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
REVENUES AND OTHER:
Oil and gas production revenues	$ 4,146	$ 4,457
Other	(70)	79
Total revenues and other	4,076	4,536
Oil and gas property and equipment
Recurring	1,265	1,135
Additional	65	521
Other assets	105	84
Asset retirement obligation accretion	65	55
Lease operating expenses	771	673
Gathering and transportation	74	77
Taxes other than income	242	257
General and administrative	116	128
Merger, acquisitions & transition		6
Financing costs, net	53	40
Total operating expenses	2,756	2,976
INCOME BEFORE INCOME TAXES	1,320	1,560
Current income tax provision	497	725
Deferred income tax provision	106	38
NET INCOME	717	797
Preferred stock dividends	19	19
NET INCOME ATTRIBUTABLE TO COMMON STOCK	$ 698	$ 778
NET INCOME PER COMMON SHARE
Basic	$ 1.78	$ 2.02
Diluted	$ 1.76	$ 2.00
WEIGHTED-AVERAGE NUMBER OF COMMON SHARES OUTSTANDING:
Basic	392	385
Diluted	408	399
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.20	$ 0.17