CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) (in thousands, except per share amounts) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating revenues:
Oil, gas, and NGL production revenue	$ 329,165	$ 366,615	$ 832,130	$ 1,201,186
Net gain on divestiture activity (note 3)	22,388	2,415	3,413	38,497
Other operating revenues	1,107	2,121	2,007	13,548
Total operating revenues and other income	352,660	371,151	837,550	1,253,231
Operating expenses:
Oil, gas, and NGL production expense	152,524	184,568	445,658	554,404
Depletion, depreciation, amortization, and asset retirement obligation liability accretion	193,966	243,879	619,193	680,984
Exploration	13,482	19,679	41,942	82,627
Impairment of proved properties	8,049	55,990	277,834	124,430
Abandonment and impairment of unproved properties	3,568	6,600	5,917	24,046
General and administrative	32,679	37,782	93,117	124,026
Change in Net Profits Plan liability	(8,314)	(4,364)	(6,449)	(13,174)
Derivative (gain) loss	(28,037)	(212,253)	121,086	(285,491)
Other operating expenses	2,397	7,166	14,180	34,589
Total operating expenses	370,314	339,047	1,612,478	1,326,441
Income (loss) from operations	(17,654)	32,104	(774,928)	(73,210)
Non-operating income (expense):
Interest expense	(47,206)	(33,157)	(112,329)	(96,583)
Gain (loss) on extinguishment of debt	0	0	15,722	(16,578)
Other, net	221	27	232	623
Loss before income taxes	(64,639)	(1,026)	(871,303)	(185,748)
Income tax benefit	23,732	4,140	314,505	78,296
Net income (loss)	$ (40,907)	$ 3,114	$ (556,798)	$ (107,452)
Basic weighted-average common shares outstanding	78,468	67,961	71,574	67,638
Diluted weighted-average common shares outstanding	78,468	68,119	71,574	67,638
Basic net income (loss) per common share	$ (0.52)	$ 0.05	$ (7.78)	$ (1.59)
Diluted net income (loss) per common share	(0.52)	0.05	(7.78)	(1.59)
Dividends per common share	$ 0.05	$ 0.05	$ 0.10	$ 0.10