Consolidated balance sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 48,960	$ 27,732
Accounts receivable, net	65,780	60,363
Inventories, net	5,774	5,138
Prepaid expenses	2,312	2,661
Total current assets	122,826	95,894
Property and equipment, net	43,996	50,641
Oil and natural gas properties, using the full cost method:
Proved	771,028	634,294
Unevaluated (excluded from the amortization base)	558,081	482,239
Accumulated depreciation, depletion, amortization and impairment	(179,540)	(124,180)
Total oil and natural gas properties	1,149,569	992,353
Other assets	446	418
Total assets	1,316,837	1,139,306
Current liabilities:
Accounts payable and accrued liabilities	66,614	75,414
Accrued payroll and benefits payable	8,315	11,276
Accrued interest payable	7,057	187
Revenue distribution payable	28,470	17,966
Long-term debt and capital leases, classified as current	3,444	3,273
Derivative instruments	29,905	8,959
Total current liabilities	143,805	117,075
Long-term debt and capital leases, less current maturities	305,760	141,386
Derivative instruments	39,042	4,167
Deferred compensation	453	696
Asset retirement obligations	24,358	33,216
Commitments and contingencies (Note 10)
Stockholders’ equity:
Preferred stock, 5,000,000 shares authorized, none issued and outstanding	0	0
Additional paid in capital	972,229	961,200
Treasury stock, at cost, 256,895 and nil shares as of September 30, 2018 and December 31, 2017	(4,872)	0
Accumulated deficit	(164,405)	(118,902)
Accumulated deficit	803,419	842,766
Total liabilities and stockholders' equity	1,316,837	1,139,306
Class A Common stock, $0.01 par value, 180,000,000 shares authorized; 38,845,797 issued and 38,588,902 outstanding at September 30, 2018 and 38,956,250 shares issued and outstanding at December 31, 2017
Stockholders’ equity:
Common stock	388	389
Class B Common stock, $0.01 par value, 20,000,000 shares authorized and 7,871,512 shares issued and outstanding at September 30, 2018 and December 31, 2017
Stockholders’ equity:
Common stock	$ 79	$ 79