CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (in thousands, except share data) - USD ($) $ in Thousands	Jan. 01, 2018	Sep. 30, 2018		Dec. 31, 2017
Current assets:
Cash and cash equivalents		$ 176,806		$ 313,943
Accounts receivable		179,347		160,154
Derivative assets		81,163		64,266
Prepaid expenses and other		15,826		10,752
Total current assets		453,142		549,115
Property and equipment (successful efforts method):
Proved oil and gas properties		6,686,922		6,139,379
Accumulated depletion, depreciation, and amortization		(3,240,124)		(3,171,575)
Unproved oil and gas properties		1,892,557		2,047,203
Wells in progress		328,808		321,347
Properties held for sale, net		5,040		111,700
Other property and equipment, net of accumulated depreciation of $56,067 and $49,985, respectively		102,984		106,738
Total property and equipment, net		5,776,187		5,554,792
Noncurrent assets:
Derivative assets		8,853		40,362
Other noncurrent assets		35,539		32,507
Total noncurrent assets		44,392		72,869
Total assets		6,273,721		6,176,776
Current liabilities:
Accounts payable and accrued expenses		429,698		386,630
Derivative liabilities		304,159		172,582
Total current liabilities		733,857		559,212
Noncurrent liabilities:
Revolving credit facility		0		0
Senior Notes, net of unamortized deferred financing costs		2,447,290		2,769,663
Senior Convertible Notes, net of unamortized discount and deferred financing costs		145,662		139,107
Asset retirement obligations		88,149		103,026
Asset retirement obligations associated with oil and gas properties held for sale		0		11,369
Deferred income taxes		140,949		79,989
Derivative liabilities		72,605		71,402
Other noncurrent liabilities		45,810		48,400
Total noncurrent liabilities		2,940,465		3,222,956
Commitments and contingencies (note 6)
Stockholders’ equity:
Common stock, $0.01 par value - authorized: 200,000,000 shares; issued and outstanding: 112,137,582 and 111,687,016 shares, respectively		1,121		1,117
Additional paid-in capital		1,758,205		1,741,623
Retained earnings		856,111	[1]	665,657
Accumulated other comprehensive loss		(16,038)	[1]	(13,789)
Total stockholders’ equity		2,599,399		2,394,608
Total liabilities and stockholders’ equity		$ 6,273,721		$ 6,176,776
Accounting Standards Update 2018-02 [Member]
Cumulative Effect on Retained Earnings, Net of Tax	$ 3,000

[1] (1) The Company reclassified $3.0 million of tax effects stranded in accumulated other comprehensive loss to retained earnings as of January 1, 2018. Please refer to Note 1 - Summary of Significant Accounting Policies for further detail.