CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 30,125	$ 99,143
Restricted cash - other	1,855	2,165
Accounts receivable, net	58,992	71,277
Derivative contracts	0	1,310
Prepaid expenses	3,582	5,248
Other current assets	411	15,954
Total current assets	94,965	195,097
Oil and natural gas properties, using full cost method of accounting
Proved	1,145,667	1,056,806
Unproved	87,268	100,884
Less: accumulated depreciation, depletion and impairment	(515,822)	(460,431)
Net oil and natural gas properties capitalized costs	717,113	697,259
Other property, plant and equipment, net	213,903	225,981
Other assets	1,274	1,290
Total assets	1,027,255	1,119,627
Current liabilities
Accounts payable and accrued expenses	120,550	139,155
Derivative contracts	35,283	10,627
Asset retirement obligations	39,981	41,017
Other current liabilities	1,714	8,115
Total current liabilities	197,528	198,914
Long-term debt	0	37,502
Derivative contracts	8,642	3,568
Asset retirement obligations	38,204	36,527
Other long-term obligations	2,625	3,176
Total liabilities	246,999	279,687
Commitments and contingencies (Note 11)
Stockholders’ Equity
Common stock, $0.001 par value; 250,000 shares authorized; 35,332 issued and outstanding at June 30, 2018 and 35,650 issued and outstanding at December 31, 2017	35	36
Warrants	88,514	88,500
Additional paid-in capital	1,053,595	1,038,324
Accumulated deficit	(361,888)	(286,920)
Total stockholders’ equity	780,256	839,940
Total liabilities and stockholders’ equity	$ 1,027,255	$ 1,119,627

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

Name:	us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.