CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,745	$ 34,740
Restricted cash	0	487
Accounts receivable	24,086	23,377
Unbilled receivables	4,907	1,192
Inventories	11,546	9,532
Prepaid expenses and other current assets	4,829	3,849
Total current assets	47,113	73,177
Property, plant and equipment, net	223,993	171,762
Intangible assets, net	19,686	0
Goodwill	16,892	0
Deferred financing costs, net	438	892
Other assets	3,360	971
Total assets	311,482	246,802
Current liabilities:
Accounts payable	13,367	26,123
Accrued and other expenses	11,372	7,576
Deferred revenue	4,805	0
Current portion of equipment financing obligations	432	572
Current portion of notes payable	0	288
Total current liabilities	29,976	34,559
Revolving credit facility, net	44,654	0
Deferred tax liabilities, long-term, net	15,886	13,239
Asset retirement obligation	9,476	8,982
Contingent consideration	9,200	0
Total liabilities	109,192	56,780
Commitments and contingencies (Note 18)
Stockholders’ equity
Common stock, $0.001 par value, 350,000,000 shares authorized; 40,639,837 issued and 40,529,182 outstanding at June 30, 2018; 40,474,085 issued and 40,393,033 outstanding at December 31, 2017	40	40
Treasury stock, at cost, 110,655 and 81,052 shares at June 30, 2018 and December 31, 2017, respectively	(839)	(666)
Additional paid-in capital	160,428	159,059
Retained earnings	42,585	31,589
Accumulated other comprehensive income	76	0
Total stockholders’ equity	202,290	190,022
Total liabilities and stockholders’ equity	$ 311,482	$ 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).

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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.