CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) (in thousands, except per share amounts) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Operating revenues:
Oil, gas, and NGL production revenue	$ 393,315		$ 623,109
Gain (Loss) on Disposition of Oil and Gas Property	(35,802)		2,958
Other operating revenues	8,421		6,653
Total operating revenues and other income	365,934		632,720
Operating expenses:
Oil, gas, and NGL production expense	196,151		163,709
Depletion, depreciation, amortization, and asset retirement obligation liability accretion	217,401		177,215
Exploration	37,407		21,335
Impairment of proved properties	55,526		0
Abandonment and impairment of unproved properties	11,627		2,801
General and administrative	43,639		35,051
Change in Net Profits Plan liability	(4,334)		(1,776)
Derivative (gain) loss	154,167	[1]	(97,662)	[1]
Other operating expenses	17,119		8,089
Total operating expenses	420,369		504,086
Income (loss) from operations	(54,435)		128,634
Non-operating income (expense):
Other, net	571		26
Interest expense	(32,647)		(24,190)
Income (loss) before income taxes	(86,511)		104,470
Income tax (expense) benefit	33,453		(38,863)
Net income (loss)	$ (53,058)		$ 65,607
Basic weighted-average common shares outstanding	67,463		67,056
Diluted weighted-average common shares outstanding	67,463		68,126
Basic net income (loss) per common share	$ (0.79)		$ 0.98
Diluted net income (loss) per common share	$ (0.79)		$ 0.96
Dividends per common share	$ 0.05		$ 0.05

[1] (2) Total derivative (gain) loss is reported in the derivative (gain) loss line item on the condensed consolidated statements of cash flows within net cash provided by operating activities.