Supplemental Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Data [Abstract]
Oil, natural gas and natural gas liquids sales		$ 352,038	$ 427,245	$ 496,419	$ 450,569	$ 766,354	$ 937,458	$ 967,850	$ 938,877	$ 1,726,271	$ 3,610,539	$ 2,073,240
Gains (losses) on oil and natural gas derivatives		273,567	549,029	(191,188)	424,781	1,404,758	451,702	(408,788)	(241,493)	1,063,082	1,206,179	177,857
Total revenues and other		646,655	998,304	321,828	916,547	2,217,650	1,435,115	596,951	733,587	2,883,334	4,983,303	2,331,655
Total expenses (1)	[1]	3,497,486	2,790,081	578,586	1,136,442	2,533,947	1,320,157	664,452	674,568
(Gains) losses on sale of assets and other, net		(146)	(166,980)	(17,996)	(12,287)	(338,750)	(35,803)	5,467	2,586	(197,409)	(366,500)	13,637
Net loss		$ (2,472,207)	$ (1,569,317)	$ (379,127)	$ (339,160)	$ (154,502)	$ (4,100)	$ (207,870)	$ (85,337)	$ (4,759,811)	$ (451,809)	$ (691,337)
Net loss per unit:
Basic		$ (7.05)	$ (4.47)	$ (1.12)	$ (1.03)	$ (0.47)	$ (0.02)	$ (0.64)	$ (0.27)	$ (13.87)	$ (1.40)	$ (2.94)
Diluted		$ (7.05)	$ (4.47)	$ (1.12)	$ (1.03)	$ (0.47)	$ (0.02)	$ (0.64)	$ (0.27)	$ (13.87)	$ (1.40)	$ (2.94)

[1] Includes the following expenses: lease operating, transportation, marketing, general and administrative, exploration, depreciation, depletion and amortization, impairment of long-lived assets and taxes, other than income taxes.