CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) (in thousands, except per share amounts) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Operating revenues:
Oil, gas, and NGL production revenue	$ 441,256	$ 654,661	$ 834,571	$ 1,277,770
Gain on divestiture activity	71,884	2,526	36,082	5,484
Other operating revenues	3,006	17,793	11,427	24,446
Total operating revenues and other income	516,146	674,980	882,080	1,307,700
Operating expenses:
Oil, gas, and NGL production expense	173,685	177,598	369,836	341,307
Depletion, depreciation, amortization, and asset retirement obligation liability accretion	219,704	187,781	437,105	364,996
Exploration	25,541	24,270	62,948	45,605
Impairment of proved properties	12,914	0	68,440	0
Abandonment and impairment of unproved properties	5,819	164	17,446	2,965
General and administrative	42,605	38,115	86,244	73,166
Change in Net Profits Plan liability	(4,476)	(7,105)	(8,810)	(8,881)
Derivative (gain) loss	80,929	126,469	(73,238)	224,131
Other operating expenses	10,304	5,972	27,423	14,061
Total operating expenses	567,025	553,264	987,394	1,057,350
Income (loss) from operations	(50,879)	121,716	(105,314)	250,350
Non-operating income (expense):
Other, net	25	(1,847)	596	(1,821)
Interest expense	(30,779)	(24,040)	(63,426)	(48,230)
Loss on extinguishment of debt	(16,578)	0	(16,578)	0
Income (loss) before income taxes	(98,211)	95,829	(184,722)	200,299
Income tax (expense) benefit	40,703	(36,049)	74,156	(74,912)
Net income (loss)	$ (57,508)	$ 59,780	$ (110,566)	$ 125,387
Basic weighted-average common shares outstanding	67,483	67,069	67,473	67,063
Diluted weighted-average common shares outstanding	67,483	68,239	67,473	68,180
Basic net income (loss) per common share	$ (0.85)	$ 0.89	$ (1.64)	$ 1.87
Diluted net income (loss) per common share	(0.85)	0.88	(1.64)	1.84
Dividends per common share	$ 0.00	$ 0.00	$ 0.05	$ 0.05