Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 4,542	$ 2,538
Accounts receivable
Oil, natural gas liquid and natural gas sales	14,936	12,289
Joint interest owners and others, net	2,722	794
Related parties	184	162
Derivative financial instruments	28	472
Prepaid expenses and other	2,216	2,365
Total current assets	24,628	18,620
Oil and gas properties, using the successful efforts method of accounting
Proved properties	895,983	750,226
Unproved properties	77,561	78,655
Other property and equipment	16,951	15,763
Less accumulated depreciation, depletion, amortization and impairment	(346,078)	(274,374)
Property and equipment, net	644,417	570,270
Deferred tax assets, net	2,376	0
Derivative financial instruments	288	0
Other non-current assets	1,554	2,918
Total assets	673,263	591,808
Current liabilities
Accounts payable	33,126	25,901
Accounts payable -- related parties	284	389
Oil, natural gas liquid and natural gas sales payable	13,705	8,747
Accrued liabilities	27,130	16,583
Derivative financial instruments	42,558	12,336
Total current liabilities	116,803	63,956
Long-term liabilities
Long-term debt	377,617	301,155
Asset retirement obligations	6,002	5,649
Deferred tax liabilities, net	0	4,769
Equity warrant liability	1,231	508
Equity warrant liability -- related parties	2,345	963
Derivative financial instruments	17,954	9,802
Other non-current liabilities	5,873	1,316
Total long-term liabilities	411,022	324,162
Commitments and contingencies (Note 12)
Stockholders' Equity
Series A-1 convertible participating preferred stock, $0.001 par value, 89,764 and 83,968 shares issued and outstanding, respectively	0	0
Additional paid-in capital	174,459	174,871
Accumulated deficit	(171,676)	(113,836)
Total stockholders' equity	145,438	203,690
Total liabilities and stockholders' equity	673,263	591,808
Class A Voting Common Stock
Stockholders' Equity
Common stock	142,655	142,655
Total stockholders' equity	142,655	142,655
Class B Non-Voting Common Stock
Stockholders' Equity
Common stock	$ 0	$ 0