Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net Operating Revenues
Crude Oil and Condensate	$ 1,059,690	$ 1,452,756	$ 1,813,401	$ 2,713,000
Natural Gas Liquids	111,643	103,930	186,962	215,920
Natural Gas	155,983	274,038	321,486	561,820
Gains on Mark-to-Market Commodity Derivative Contracts	(44,373)	(48,493)	(38,938)	27,715
Gathering, Processing and Marketing	485,256	678,356	819,209	1,248,626
Losses on Asset Dispositions, Net	(15,550)	(5,564)	(6,403)	(3,957)
Other, Net	23,091	14,678	34,372	25,115
Total	1,775,740	2,469,701	3,130,089	4,788,239
Operating Expenses
Lease and Well	218,393	289,664	459,258	651,145
Transportation Costs	179,471	209,833	369,925	438,145
Gathering and Processing Costs	29,226	34,997	57,750	71,006
Exploration Costs	30,559	43,755	60,388	83,204
Dry Hole Costs	(172)	(551)	74	14,119
Impairments	72,714	68,519	144,331	137,955
Marketing Costs	480,046	670,169	820,900	1,308,831
Depreciation, Depletion and Amortization	862,491	909,227	1,791,382	1,822,015
General and Administrative	97,705	82,324	198,236	166,621
Taxes Other Than Income	93,480	122,138	154,159	228,567
Total	2,063,913	2,430,075	4,056,403	4,921,608
Operating Income (Loss)	(288,173)	39,626	(926,314)	(133,369)
Other Income (Expense), Net	(20,996)	9,380	(25,433)	(611)
Income (Loss) Before Interest Expense and Income Taxes	(309,169)	49,006	(951,747)	(133,980)
Interest Expense
Interest Expense, Net	71,108	60,484	139,498	113,829
Loss Before Income Taxes	(380,277)	(11,478)	(1,091,245)	(247,809)
Income Tax Benefit	(87,719)	(16,746)	(326,911)	(83,329)
Net Income (Loss)	$ (292,558)	$ 5,268	$ (764,334)	$ (164,480)
Net Income (Loss) Per Share
Basic	$ (0.53)	$ 0.01	$ (1.40)	$ (0.30)
Diluted	(0.53)	0.01	(1.40)	(0.30)
Dividends Declared per Common Share	$ 0.1675	$ 0.1675	$ 0.3350	$ 0.3350
Average Number of Common Shares
Basic	547,335	545,504	547,029	545,245
Diluted	547,335	549,683	547,029	545,245
Comprehensive Income (Loss)
Net Income (Loss)	$ (292,558)	$ 5,268	$ (764,334)	$ (164,480)
Other Comprehensive Income (Loss)
Foreign Currency Translation Adjustments	5,844	8,404	8,029	(4,763)
Other	23	27	45	(184)
Other Comprehensive Income (Loss)	5,867	8,431	8,074	(4,947)
Comprehensive Income (Loss)	$ (286,691)	$ 13,699	$ (756,260)	$ (169,427)