CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,186	$ 34,740
Restricted cash	0	487
Accounts receivable	29,666	23,377
Unbilled receivables	1,424	1,192
Inventories	16,402	9,532
Prepaid expenses and other current assets	4,867	3,849
Total current assets	53,545	73,177
Property, plant and equipment, net	233,181	171,762
Intangible assets, net	19,398	0
Goodwill	16,935	0
Deferred financing costs, net	388	892
Other assets	3,455	971
Total assets	326,902	246,802
Current liabilities:
Accounts payable	10,798	26,123
Accrued and other expenses	16,394	7,576
Deferred revenue	4,030	0
Current portion of equipment financing obligations	8	572
Current portion of notes payable	0	288
Total current liabilities	31,230	34,559
Revolving credit facility, net	44,190	0
Deferred tax liabilities, long-term, net	20,497	13,239
Asset retirement obligation	8,654	8,982
Contingent consideration	7,100	0
Total liabilities	111,671	56,780
Commitments and contingencies (Note 18)
Stockholders’ equity
Common stock, $0.001 par value, 350,000,000 shares authorized; 40,661,188 issued and 40,550,353 outstanding at September 30, 2018; 40,474,085 issued and 40,393,033 outstanding at December 31, 2017	40	40
Treasury stock, at cost, 110,835 and 81,052 shares at September 30, 2018 and December 31, 2017, respectively	(840)	(666)
Additional paid-in capital	161,375	159,059
Retained earnings	54,710	31,589
Accumulated other comprehensive loss	(54)	0
Total stockholders’ equity	215,231	190,022
Total liabilities and stockholders’ equity	$ 326,902	$ 246,802

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccountsPayableCurrent
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.