Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ (94,130)	$ (97,921)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities
Depreciation and amortization	85,668	94,150
Impaired asset expense and inventory write-downs	7,080	0
Accretion on asset retirement obligation	607	115
Change in allowance for doubtful accounts	711	278
Amortization of deferred financing costs	1,745	586
Amortization of debt discounts	789	3,708
Non-cash compensation	8,237	21,995
Loss on disposal of assets	2,634	3,891
Deferred income taxes	0	(78)
Changes in operating assets and liabilities:
Accounts receivable	20,401	(7,977)
Inventories	4,546	313
Prepaid expenses and other current assets	2,404	7,010
Other assets	(8)	(49)
Accounts payable	(31,617)	5,736
Income tax receivable	1,574	291
Other liabilities	131	8,629
Accrued expenses	17,740	15,705
Net cash provided by operating activities	28,512	56,382
Cash flows from investing activities:
Purchase of property and equipment	(46,263)	(48,588)
Proceeds from sale of assets	7,122	1,942
Payments for other long-term assets	(411)	0
Net cash used in investing activities	(39,552)	(46,646)
Cash flows from financing activities:
Proceeds from debt	0	32,500
Payments of debt	(23,209)	(50,313)
Change in treasury stock including restricted stock issuances	(5,122)	(1,717)
Deferred loan costs and other financing activities	(469)	(585)
Net cash used in financing activities	(28,800)	(20,115)
Net decrease in cash and cash equivalents	(39,840)	(10,379)
Cash and cash equivalents - beginning of period	90,300	86,223
Cash and cash equivalents - end of period	50,460	75,844
Noncash investing and financing activity:
Finance leases and notes issued for equipment	7,943	16,565
Change in accrued property and equipment	310	3,675
Change in asset retirement obligations	$ 6,420	$ (148)