Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 2,038	$ 2,538
Accounts receivable
Oil, natural gas liquid and natural gas sales	12,537	12,289
Joint interest owners and others, net	770	794
Related parties	70	162
Derivative financial instruments	385	472
Prepaid expenses and other	1,509	2,365
Total current assets	17,309	18,620
Proved properties	783,356	750,226
Unproved properties	79,091	78,655
Other property and equipment	16,668	15,763
Less accumulated depreciation, depletion and amortization	(289,484)	(274,374)
Net property and equipment	589,631	570,270
Derivative financial instruments	245
Other non-current assets	2,479	2,918
Total assets	609,664	591,808
Current liabilities
Accounts payable	25,466	25,901
Accounts payable -- related parties	321	389
Oil, natural gas liquid and natural gas sales payable	8,714	8,747
Accrued liabilities	20,715	16,583
Derivative financial instruments	19,556	12,336
Total current liabilities	74,772	63,956
Long-term debt	325,759	301,155
Asset retirement obligations	5,723	5,649
Deferred tax liabilities, net	1,577	4,769
Equity warrant liability	560	508
Equity warrant liability -- related parties	1,063	963
Derivative financial instruments	10,782	9,802
Other non-current liabilities	2,668	1,316
Total long-term liabilities	348,132	324,162
Commitments and contingencies (Note 11)
Stockholders' Equity
Series A-1 convertible participating preferred stock, $0.001 par value, 85,857 and 83,968 shares issued and outstanding, respectively
Additional paid-in capital	174,477	174,871
Accumulated deficit	(130,372)	(113,836)
Total stockholders' equity	186,760	203,690
Total liabilities and stockholders' equity	609,664	591,808
Class A Voting Common Stock
Stockholders' Equity
Common stock	142,655	142,655
Total stockholders' equity	$ 142,655	$ 142,655