CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010
Revenues
Sales and other operating revenues	$ 28,616,331	$ 27,582,423	[1]	$ 20,092,836	[1]
Gain (loss) on sale of assets	(1,258)	22,679	[1]	884	[1]
Interest and other income (loss)	10,973	33,019	[1]	(57,570)	[1]
Total revenues	28,626,046	27,638,121	[1]	20,036,150	[1]
Costs and Expenses
Crude oil and product purchases	22,449,306	21,875,297	[1]	15,351,318	[1]
Operating expenses	2,127,503	1,964,891	[1]	1,651,623	[1]
Exploration expenses, including undeveloped lease amortization	380,924	489,346	[1]	276,089	[1]
Selling and general expenses	354,493	297,520	[1]	256,471	[1]
Depreciation, depletion and amortization	1,375,577	1,079,750	[1]	1,092,107	[1]
Impairment of properties	260,988	368,600	[1]	0	[1]
Accretion of asset retirement obligations	39,341	34,724	[1]	29,580	[1]
Redetermination of Terra Nova working interest	0	(5,351)	[1],[2]	18,582	[1],[2]
Interest expense	54,105	55,831	[1]	53,172	[1]
Interest capitalized	(39,173)	(15,131)	[1]	(18,444)	[1]
Total costs and expenses	27,003,064	26,145,477	[1]	18,710,498	[1]
Income from continuing operations before income taxes	1,622,982	1,492,644	[1]	1,325,652	[1]
Income tax expense	658,936	763,173	[1]	576,572	[1]
Income from continuing operations	964,046	729,471	[1]	749,080	[1]
Income from discontinued operations, net of income taxes	6,830	143,231	[1]	49,001	[1]
Net Income	$ 970,876	$ 872,702	[1]	$ 798,081	[1]
Income per Common Share - Basic
Income from continuing operations	$ 4.97	$ 3.77	[1]	$ 3.90	[1]
Income from discontinued operations	$ 0.04	$ 0.74	[1]	$ 0.26	[1]
Net Income - Basic	$ 5.01	$ 4.51	[1]	$ 4.16	[1]
Income per Common Share - Diluted
Income from continuing operations	$ 4.95	$ 3.75	[1]	$ 3.88	[1]
Income from discontinued operations	$ 0.04	$ 0.74	[1]	$ 0.25	[1]
Net Income - Diluted	$ 4.99	$ 4.49	[1]	$ 4.13	[1]
Average Common shares outstanding - basic	193,902,335	193,409,621	[1]	191,830,357	[1]
Average Common shares outstanding - diluted	194,668,737	194,512,402	[1]	193,157,814	[1]

[1] Reclassified to conform to current presentation.

[2] Results exclude corporate overhead, interest and discontinued operations.