Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 118,512	$ 172,000
Accounts receivable, net of allowance for doubtful accounts of $19,534 and $29,037 at June 30, 2018 and December 31, 2017, respectively	441,983	398,056
Income taxes receivable		959
Prepaid expenses	43,188	42,128
Inventory and other current assets	158,765	134,032
Assets held for sale		13,644
Total current assets	762,448	760,819
Property, plant and equipment, net of accumulated depreciation and depletion of $2,848,297 and $2,736,620 at June 30, 2018 and December 31, 2017, respectively	1,240,703	1,316,944
Goodwill	806,813	807,860
Notes receivable	62,041	60,149
Restricted cash	11,631	20,483
Intangible and other long-term assets, net of accumulated amortization of $89,561 and $83,359 at June 30, 2018 and December 31, 2017, respectively	137,349	143,970
Total assets	3,020,985	3,110,225
Current liabilities:
Accounts payable	162,125	119,716
Accrued expenses	201,665	221,757
Current portion of decommissioning liabilities	24,156	27,261
Liabilities held for sale		6,463
Total current liabilities	387,946	375,197
Deferred income taxes	41,758	61,058
Decommissioning liabilities	103,088	103,136
Long-term debt, net	1,281,145	1,279,771
Other long-term liabilities	154,333	158,634
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 - 154,525,627 at June 30, 2018, Authorized - 250,000,000, Issued and Outstanding - 153,263,097 at December 31, 2017	155	153
Additional paid in capital	2,722,224	2,713,161
Accumulated other comprehensive loss, net	(70,092)	(67,427)
Retained deficit	(1,599,572)	(1,513,458)
Total stockholders' equity	1,052,715	1,132,429
Total liabilities and stockholders' equity	$ 3,020,985	$ 3,110,225