Consolidated Statements of Income and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net Operating Revenues
Crude Oil and Condensate	$ 1,512,168	$ 953,154	$ 4,198,753	$ 2,649,034
Natural Gas Liquids	170,351	206,572	518,684	539,104
Natural Gas	426,728	576,803	1,153,433	1,760,715
Gains on Mark-to-Market Commodity Derivative Contracts	4,671	357,664	327,328	480,539
Gathering, Processing and Marketing	764,385	578,022	2,193,290	1,461,303
Gains on Asset Dispositions, Net	67,376	207,468	248,134	442,981
Other, Net	9,176	6,061	31,203	19,424
Total	2,954,855	2,885,744	8,670,825	7,353,100
Operating Expenses
Lease and Well	253,452	248,926	765,703	680,710
Transportation Costs	164,407	108,678	431,642	308,276
Gathering and Processing Costs	26,223	18,532	72,403	55,444
Exploration Costs	45,953	48,469	136,909	140,616
Dry Hole Costs	1,924	22,604	13,005	47,231
Impairments	62,875	83,431	250,239	531,413
Marketing Costs	755,457	572,604	2,155,043	1,427,450
Depreciation, Depletion and Amortization	825,851	651,684	2,383,359	1,822,854
General and Administrative	92,870	82,260	244,866	219,703
Taxes Other Than Income	120,096	98,526	359,798	308,669
Total	2,349,108	1,935,714	6,812,967	5,542,366
Operating Income	605,747	950,030	1,857,858	1,810,734
Other Income, Net	7,596	1,377	22,902	11,205
Income Before Interest Expense and Income Taxes	613,343	951,407	1,880,760	1,821,939
Interest Expense, Net	53,154	52,186	154,198	153,772
Income Before Income Taxes	560,189	899,221	1,726,562	1,668,167
Income Tax Provision	204,698	358,343	651,284	697,742
Net Income	355,491	540,878	1,075,278	970,425
Net Income Per Share
Basic	$ 1.33	$ 2.03	$ 4.03	$ 3.71
Diluted	$ 1.31	$ 2.01	$ 3.98	$ 3.66
Dividends Declared per Common Share	$ 0.17	$ 0.16	$ 0.51	$ 0.48
Average Number of Common Shares
Basic	267,941	266,053	267,136	261,664
Diluted	270,982	269,292	270,328	265,245
Comprehensive Income
Net Income	355,491	540,878	1,075,278	970,425
Other Comprehensive Income (Loss)
Foreign Currency Translation Adjustments	50,426	(119,338)	48,262	(63,823)
Foreign Currency Swap	1,708	646	2,338	462
Income Tax Related to Foreign Currency Swap	(646)	(166)	(597)	(114)
Interest Rate Swap	(318)	(2,503)	(682)	(6,612)
Income Tax Related to Interest Rate Swap	114	901	245	2,378
Other	29	28	87	86
Other Comprehensive Income (Loss)	51,313	(120,432)	49,653	(67,623)
Comprehensive Income	$ 406,804	$ 420,446	$ 1,124,931	$ 902,802