Consolidated Statements Of Operations - USD ($) $ in Thousands, shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues and other income:
Oil and gas	$ 768,000	$ 613,000	$ 1,577,000	$ 1,022,000
Sales of purchased oil and gas	517,000	395,000	1,001,000	618,000
Interest and other	16,000	6,000	30,000	13,000
Derivative gains, net	135,000	(229,000)	286,000	(186,000)
Gain (loss) on disposition of assets, net	194,000	1,000	205,000	3,000
Total revenues and other income	1,630,000	786,000	3,099,000	1,470,000
Costs and expenses:
Oil and gas production	147,000	141,000	288,000	297,000
Production and ad valorem taxes	51,000	36,000	99,000	65,000
Depletion, depreciation and amortization	341,000	384,000	678,000	737,000
Purchased oil and gas	531,000	410,000	1,034,000	653,000
Impairment of oil and gas properties	0	0	285,000	32,000
Exploration and abandonments	26,000	18,000	59,000	77,000
General and administrative	81,000	80,000	165,000	154,000
Accretion of discount on asset retirement obligations	5,000	5,000	10,000	9,000
Interest	35,000	56,000	81,000	111,000
Other	59,000	67,000	119,000	154,000
Costs and Expenses	1,276,000	1,197,000	2,818,000	2,289,000
Income (loss) from continuing operations before income taxes	354,000	(411,000)	281,000	(819,000)
Income tax provision	$ (121,000)	143,000	$ (90,000)	284,000
Net income (loss) attributable to common stockholders		$ (268,000)		$ (535,000)
Basic earnings per share:
Basic and diluted net loss per share attributable to common stockholders	$ 1.36	$ (1.63)	$ 1.11	$ (3.28)
Weighted average shares outstanding:
Basic weighted average shares outstanding	170	164	170	163
Diluted	170	164	170	163
Dividends declared per share	$ 0.00	$ 0.00	$ 0.04	$ 0.04
Retained Earnings [Member]
Costs and expenses:
Net income (loss) attributable to common stockholders	$ 233,000		$ 191,000