CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	$ 44,658	$ 32,774
Accounts receivable, net of allowance for doubtful accounts	57,473	72,943
Derivative assets	1,419	81,166
Prepayments and other current assets	3,495	2,898
Total current assets	107,045	189,781
Property and equipment - at cost, successful efforts method for oil and gas properties:
Proved oil and gas properties	2,296,671	2,195,310
Unproved oil and gas properties, excluded from amortization	490,868	468,208
Furniture, equipment and other	29,675	20,662
Property, plant and equipment, gross	2,817,214	2,684,180
Accumulated depreciation, depletion, amortization and impairment	721,054	654,657
Total property and equipment, net	2,096,160	2,029,523
Derivative assets	3,939	27,289
Other noncurrent assets	5,392	5,867
Total	2,212,536	2,252,460
Current Liabilities:
Accounts payable and accrued liabilities	135,762	131,379
Amounts payable to oil and gas property owners	44,886	55,792
Production taxes payable	63,257	59,155
Derivative liabilities	5,850	0
Current portion of long-term debt	0	1,859
Total current liabilities	249,755	248,185
Long-term debt, net of debt issuance costs	687,768	617,387
Asset retirement obligations	27,324	27,330
Deferred income taxes	109,823	139,534
Other noncurrent liabilities	21,391	7,926
Commitments and contingencies (Note 12)
Stockholders' Equity:
Common stock, $0.001 par value; authorized 400,000,000 shares; 213,761,384 and 212,477,101 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively, with 3,431,780 and 2,912,166 shares subject to restrictions, respectively	210	210
Additional paid-in capital	1,772,336	1,771,730
Retained earnings (accumulated deficit)	(656,071)	(559,842)
Treasury stock, at cost: zero shares at March 31, 2019 and December 31, 2018	0	0
Total stockholders' equity	1,116,475	1,212,098
Total liabilities and stockholders' equity	$ 2,212,536	$ 2,252,460