CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,466	$ 34,740
Restricted cash	0	487
Accounts receivable, net	18,989	23,377
Unbilled receivables	7,823	1,192
Inventories	18,575	9,532
Prepaid expenses and other current assets	3,243	3,849
Total current assets	50,096	73,177
Property, plant and equipment, net	248,396	171,762
Intangible assets, net	18,068	0
Deferred financing costs, net	334	892
Other assets	3,398	971
Total assets	320,292	246,802
Current liabilities:
Accounts payable	11,336	26,123
Accrued and other expenses	8,392	7,576
Deferred revenue	4,095	0
Current portion of long-term debt	829	860
Total current liabilities	24,652	34,559
Long-term debt, net of current portion	47,893	0
Deferred tax liabilities, long-term, net	17,898	13,239
Asset retirement obligation	13,322	8,982
Contingent consideration	7,167	0
Total liabilities	110,932	56,780
Commitments and contingencies (Note 17)
Stockholders’ equity
Common stock, $0.001 par value, 350,000,000 shares authorized; 40,673,513 issued and 39,974,478 outstanding at December 31, 2018; 40,474,085 issued and 40,393,033 outstanding at December 31, 2017	40	40
Treasury stock, at cost, 699,035 shares and 81,052 shares at December 31, 2018 and 2017, respectively	(2,839)	(666)
Additional paid-in capital	162,195	159,059
Retained earnings	50,277	31,589
Accumulated other comprehensive loss	(313)	0
Total stockholders’ equity	209,360	190,022
Total liabilities and stockholders’ equity	$ 320,292	$ 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.