CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) (in thousands, except per share amounts) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating revenues:
Oil, gas, and NGL production revenue	$ 211,823	$ 393,315
Net loss on divestiture activity (note 3)	(69,021)	(35,802)
Other operating revenues	274	8,421
Total operating revenues and other income	143,076	365,934
Operating expenses:
Oil, gas, and NGL production expense	144,543	196,151
Depletion, depreciation, amortization, and asset retirement obligation liability accretion	214,207	217,401
Exploration	15,273	37,407
Impairment of proved properties	269,785	55,526
Abandonment and impairment of unproved properties	2,311	11,627
General and administrative	32,238	43,639
Change in Net Profits Plan liability	(1,260)	(4,334)
Derivative gain	(14,228)	(154,167)
Other operating expenses	6,932	17,119
Total operating expenses	669,801	420,369
Loss from operations	(526,725)	(54,435)
Non-operating income (expense):
Interest income	6	571
Interest expense	(31,088)	(32,647)
Gain on Extinguishment of Debt	15,722	0
Loss before income taxes	(542,085)	(86,511)
Income tax benefit	194,875	33,453
Net loss	$ (347,210)	$ (53,058)
Basic weighted-average common shares outstanding	68,077	67,463
Diluted weighted-average common shares outstanding	68,077	67,463
Basic net loss per common share	$ (5.10)	$ (0.79)
Diluted net loss per common share	(5.10)	(0.79)
Dividends per common share	$ 0.05	$ 0.05