CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) (in thousands, except per share data) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019		Jun. 30, 2018		Jun. 30, 2019		Jun. 30, 2018
Operating revenues and other income:
Oil, gas, and NGL production revenue	$ 406,854	[1]	$ 402,558	[1]	$ 747,330	[2]	$ 785,444	[2]
Net gain on divestiture activity	262		39,501		323		424,870
Other operating revenues	56		1,857		449		3,197
Total operating revenues and other income	407,172		443,916		748,102		1,213,511
Operating expenses:
Oil, gas, and NGL production expense	123,050		117,400		244,355		238,279
Depletion, depreciation, amortization, and asset retirement obligation liability accretion	206,330		151,765		384,076		282,238
Exploration	10,877		14,056		22,225		27,783
Abandonment and impairment of unproved properties	12,417		11,935		18,755		17,560
General and administrative	30,920		28,920		63,006		56,602
Net derivative (gain) loss	(79,655)		63,749		97,426		71,278
Other operating expenses, net	(934)		(57)		(599)		4,555
Total operating expenses	303,005		387,768		829,244		698,295
Income (loss) from operations	104,167		56,148		(81,142)		515,216
Interest expense	(39,627)		(41,654)		(77,607)		(84,739)
Other non-operating income (expense), net	(562)		1,802		(879)		2,211
Income (loss) before income taxes	63,978		16,296		(159,628)		432,688
Income tax (expense) benefit	(13,590)		901		32,448		(98,090)
Net income (loss)	$ 50,388		$ 17,197		$ (127,180)		$ 334,598
Basic weighted-average common shares outstanding	112,262		111,701		112,257		111,698
Diluted weighted-average common shares outstanding	112,932		113,630		112,257		113,267
Basic net income (loss) per common share	$ 0.45		$ 0.15		$ (1.13)		$ 3.00
Diluted net income (loss) per common share	0.45		0.15		(1.13)		2.95
Dividends per common share	$ 0		$ 0		$ 0.05		$ 0.05

[1] Note: Amounts may not calculate due to rounding.

[2] Note: Amounts may not calculate due to rounding.