Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (32,137)	$ (36,499)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation expense	17,868	18,439
Amortization of debt financing costs	117	117
Amortization of debt discount	12,313	12,191
Amortization of contract value	1,556
PIK interest on the Convertible Notes	1,912	1,890
Share-based compensation expense	1,745	780
Deferred income tax (expense) benefit	419	(1,789)
Gain on disposal of assets	(2,682)
Changes in operating assets and liabilities:
Trade receivables	6,498	1,207
Inventory	(189)	293
Prepaid expenses and other current assets	120	(951)
Other assets	(383)	1,434
Accounts payable	2,051	1,668
Accrued liabilities and other long-term liabilities	(6,292)	(401)
Net cash provided by (used in) operating activities	2,916	(1,621)
CASH FLOWS FROM INVESTING ACTIVITIES
Additions to property and equipment	(19)	(2,156)
Proceeds from sale of Vantage 260	4,845
Net cash provided by (used in) investing activities	4,826	(2,156)
CASH FLOWS FROM FINANCING ACTIVITIES
Repayment of long-term debt	(5,458)	(358)
Net cash used in financing activities	(5,458)	(358)
Net (decrease) increase in cash and cash equivalents	2,284	(4,135)
Cash and cash equivalents—beginning of period	195,455	231,727
Cash and cash equivalents—end of period	197,739	227,592
Cash paid for:
Interest	6,836	2,829
Income taxes (net of refunds)	$ 2,891	$ 3,024