Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 234,132	$ 158,050
Accounts receivable, net of allowance for doubtful accounts of $13,217 and $12,080 at June 30, 2019 and December 31, 2018, respectively	369,834	447,353
Prepaid expenses	61,989	45,802
Inventory and other current assets	133,815	121,700
Total current assets	799,770	772,905
Property, plant and equipment, net of accumulated depreciation and depletion of $2,618,764 and $2,640,344 at June 30, 2019 and December 31, 2018, respectively	940,933	1,109,126
Operating lease right-of-use assets	99,004
Goodwill	136,787	136,788
Notes receivable	66,010	63,993
Restricted cash	2,739	5,698
Intangible and other long-term assets, net of accumulated amortization of $23,037 and $76,358 at June 30, 2019 and December 31, 2018, respectively	101,054	127,452
Total assets	2,146,297	2,215,962
Current liabilities:
Accounts payable	95,894	139,325
Accrued expenses	218,882	219,180
Income taxes payable	3,734	734
Current portion of decommissioning liabilities	3,593	3,538
Total current liabilities	322,103	362,777
Long-term debt, net	1,284,814	1,282,921
Decommissioning liabilities	129,604	126,558
Operating lease liabilities	78,973
Other long-term liabilities	150,412	152,967
Stockholders' equity:
Preferred stock of $0.01 par value. Authorized - 5,000,000 shares; none issued
Common stock of $0.001 par value, Authorized - 250,000,000, Issued and Outstanding - 156,573,160 at June 30, 2019, Authorized - 250,000,000, Issued and Outstanding - 154,885,418 at December 31, 2018	157	155
Additional paid in capital	2,744,373	2,735,125
Accumulated other comprehensive loss, net	(74,020)	(73,177)
Retained deficit	(2,490,119)	(2,371,364)
Total stockholders' equity	180,391	290,739
Total liabilities and stockholders' equity	$ 2,146,297	$ 2,215,962