Consolidated Statements of Income and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net Operating Revenues
Crude Oil and Condensate	$ 2,012,999	$ 1,376,250	$ 3,794,832	$ 2,686,585
Natural Gas Liquids	178,457	150,023	347,986	348,333
Natural Gas	462,602	359,421	873,481	726,705
Gains on Mark-to-Market Commodity Derivative Contracts	191,490	188,449	86,534	322,657
Gathering, Processing and Marketing	959,413	710,748	1,882,370	1,428,905
Gains on Asset Dispositions, Net	13,153	113,290	177,386	180,758
Other, Net	22,071	11,138	34,110	22,027
Total	3,840,185	2,909,319	7,196,699	5,715,970
Operating Expenses
Lease and Well	268,888	250,756	517,888	512,251
Transportation Costs	224,491	135,393	408,748	267,235
Gathering and Processing Costs	25,897	20,588	50,401	46,180
Exploration Costs	47,323	48,149	91,539	90,956
Dry Hole Costs	35,750	11,081	39,712	11,081
Impairments	37,967	54,217	91,515	187,364
Marketing Costs	965,490	694,118	1,870,139	1,399,586
Depreciation, Depletion and Amortization	910,531	808,765	1,756,919	1,557,508
General and Administrative	80,607	75,727	158,592	151,996
Taxes Other Than Income	151,197	118,186	286,128	239,702
Total	2,748,141	2,216,980	5,271,581	4,463,859
Operating Income	1,092,044	692,339	1,925,118	1,252,111
Other Income (Expense), Net	4,833	4,675	(5,301)	15,306
Income Before Interest Expense and Income Taxes	1,096,877	697,014	1,919,817	1,267,417
Interest Expense
Interest Expense, Net	61,647	50,775	123,568	101,044
Income Before Income Taxes	1,035,230	646,239	1,796,249	1,166,373
Income Tax Provision	375,538	250,461	641,832	446,586
Net Income	659,692	395,778	1,154,417	719,787
Net Income Per Share
Basic	$ 2.44	$ 1.48	$ 4.28	$ 2.70
Diluted	$ 2.42	$ 1.47	$ 4.24	$ 2.67
Dividends Declared per Common Share	$ 0.1875	$ 0.17	$ 0.375	$ 0.34
Average Number of Common Shares
Basic	270,016	266,874	269,665	266,718
Diluted	272,739	269,985	272,473	270,083
Comprehensive Income
Net Income	659,692	395,778	1,154,417	719,787
Other Comprehensive Income (Loss)
Foreign Currency Translation Adjustments	(19,314)	(28,689)	(33,578)	(2,164)
Foreign Currency Swap Transaction	(662)	(1,431)	1,039	630
Income Tax Related to Foreign Currency Swap Transaction	0	576	0	49
Interest Rate Swap Transaction	584	231	1,321	(364)
Income Tax Related to Interest Rate Swap Transaction	(210)	(83)	(475)	131
Other	27	31	55	58
Other Comprehensive Income (Loss)	(19,575)	(29,365)	(31,638)	(1,660)
Comprehensive Income	$ 640,117	$ 366,413	$ 1,122,779	$ 718,127