CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Oil sales	$ 809,664	$ 1,308,958	$ 1,250,212
Gas sales	428,227	687,930	471,045
NGL sales	179,647	375,941	231,248
Gas gathering and other	34,688	49,602	45,441
Gas marketing, net of related costs of $144,673, $256,836 and $187,772 respectively	393	1,745	105
Total revenues	1,452,619	2,424,176	1,998,051
Costs and expenses:
Impairment of oil and gas properties	3,716,883
Depreciation, depletion and amortization	778,923	806,021	615,874
Asset retirement obligation	9,121	10,082	7,989
Production	299,374	342,304	286,742
Transportation, processing and other operating	182,362	195,414	93,580
Gas gathering and other	38,138	35,113	25,876
Taxes other than income	84,764	128,793	112,732
General and administrative	74,688	81,160	77,466
Stock compensation	19,559	15,001	14,279
(Gain) loss on derivative instruments, net	(11,246)	(3,762)	209
Other operating (income) expense, net	856	116	(132,334)
Total costs and expenses	5,193,422	1,610,242	1,102,413
Operating income (loss)	(3,740,803)	813,934	895,638
Other (income) and expense:
Interest expense	85,746	72,865	54,973
Capitalized interest	(30,589)	(35,925)	(31,517)
Other, net	(13,576)	(28,907)	(21,518)
Income (loss) before income tax	(3,782,384)	805,901	893,700
Income tax expense (benefit)	(1,373,436)	298,697	329,011
Net income (loss)	$ (2,408,948)	$ 507,204	$ 564,689
Basic
Distributed (in dollars per share)	$ 0.64	$ 0.64	$ 0.56
Undistributed (in dollars per share)	(26.56)	5.15	5.92
Total basic (in dollars per share)	(25.92)	5.79	6.48
Diluted
Distributed (in dollars per share)	0.64	0.64	0.56
Undistributed (in dollars per share)	(26.56)	5.14	5.91
Total diluted (in dollars per share)	$ (25.92)	$ 5.78	$ 6.47
Comprehensive income (loss):
Net income (loss)	$ (2,408,948)	$ 507,204	$ 564,689
Other comprehensive income (loss):
Change in fair value of investments, net of tax	(661)	(87)	715
Total comprehensive income (loss)	$ (2,409,609)	$ 507,117	$ 565,404