Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net loss	$ (28,059)	$ (29,291)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	45,504	47,034
Allowance for doubtful accounts, net of recoveries	(286)	(422)
Gain on dispositions of property and equipment, net	(2,201)	(1,061)
Stock-based compensation expense	1,194	2,356
Phantom stock compensation expense	51	6,529
Amortization of debt issuance costs and discount	1,541	1,422
Impairment	1,378	2,368
Deferred income taxes	1,225	273
Change in other noncurrent assets	1,476	(199)
Change in other noncurrent liabilities	(2,493)	(10,009)
Changes in current assets and liabilities:
Receivables	(14,858)	(12,368)
Inventory	(3,864)	(3,662)
Prepaid expenses and other current assets	(108)	(785)
Accounts payable	10,697	5,858
Deferred revenues	(302)	619
Accrued expenses	(6,849)	8,463
Net cash provided by operating activities	4,046	17,125
Cash flows from investing activities:
Purchases of property and equipment	(31,382)	(31,485)
Proceeds from sale of property and equipment	3,439	2,225
Proceeds from insurance recoveries	588	541
Net cash used in investing activities	(27,355)	(28,719)
Cash flows from financing activities:
Proceeds from exercise of options	0	12
Purchase of treasury stock	(125)	(549)
Net cash used in financing activities	(125)	(537)
Net decrease in cash, cash equivalents and restricted cash	(23,434)	(12,131)
Beginning cash, cash equivalents, and restricted cash	54,564	75,648
Ending cash, cash equivalents, and restricted cash	31,130	63,517
Supplementary disclosure:
Interest paid	18,832	18,073
Income tax paid	2,156	1,789
Change in capital expenditure accruals	$ (3,766)	$ 2,440