Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Operating Revenues
Crude Oil and Condensate	$ 1,452,756	$ 2,618,975	$ 2,713,000	$ 5,016,077
Natural Gas Liquids	103,930	247,973	215,920	494,208
Natural Gas	274,038	509,091	561,820	1,065,784
Gains (Losses) on Mark-to-Market Commodity Derivative Contracts	(48,493)	(229,270)	27,715	(385,006)
Gathering, Processing and Marketing	678,356	1,027,795	1,248,626	2,043,206
Gains (Losses) on Asset Dispositions, Net	(5,564)	3,856	(3,957)	15,354
Other, Net	14,678	9,136	25,115	21,604
Total	2,469,701	4,187,556	4,788,239	8,271,227
Operating Expenses
Lease and Well	289,664	346,458	651,145	667,292
Transportation Costs	209,833	240,579	438,145	483,816
Gathering and Processing Costs	34,997	32,470	71,006	66,394
Exploration Costs	43,755	42,208	83,204	90,266
Dry Hole Costs	(551)	5,558	14,119	13,906
Impairments	68,519	39,035	137,955	152,396
Marketing Costs	670,169	1,043,515	1,308,831	2,049,819
Depreciation, Depletion and Amortization	909,227	996,602	1,822,015	1,943,093
General and Administrative	82,324	90,932	166,621	173,794
Taxes Other Than Income	122,138	205,469	228,567	401,442
Total	2,430,075	3,042,826	4,921,608	6,042,218
Operating Income (Loss)	39,626	1,144,730	(133,369)	2,229,009
Other Income (Expense), Net	9,380	7,950	(611)	4,612
Income (Loss) Before Interest Expense and Income Taxes	49,006	1,152,680	(133,980)	2,233,621
Interest Expense
Interest Expense, Net	60,484	51,867	113,829	102,019
Income (Loss) Before Income Taxes	(11,478)	1,100,813	(247,809)	2,131,602
Income Tax Provision (Benefit)	(16,746)	394,460	(83,329)	764,321
Net Income (Loss)	$ 5,268	$ 706,353	$ (164,480)	$ 1,367,281
Net Income (Loss) Per Share
Basic	$ 0.01	$ 1.30	$ (0.30)	$ 2.52
Diluted	0.01	1.29	(0.30)	2.49
Dividends Declared per Common Share	$ 0.1675	$ 0.1250	$ 0.3350	$ 0.2500
Average Number of Common Shares
Basic	545,504	543,099	545,245	542,675
Diluted	549,683	548,676	545,245	548,046
Comprehensive Income (Loss)
Net Income (Loss)	$ 5,268	$ 706,353	$ (164,480)	$ 1,367,281
Other Comprehensive Income (Loss)
Foreign Currency Translation Adjustments	8,404	24,378	(4,763)	11,448
Foreign Currency Swap Transaction	0	0	0	50
Income Tax Related to Foreign Currency Swap Transaction	0	0	0	(670)
Interest Rate Swap Transaction	0	0	0	777
Income Tax Related to Interest Rate Swap Transaction	0	0	0	(281)
Other	27	(593)	(184)	(570)
Other Comprehensive Income (Loss)	8,431	23,785	(4,947)	10,754
Comprehensive Income (Loss)	$ 13,699	$ 730,138	$ (169,427)	$ 1,378,035