Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows provided by (used in) operating activities:
Net income (loss)	$ 80,918	$ (118,895)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation, amortization and accretion	41,847	38,569
Change in fair value of derivative assets and liabilities	(106,885)	73,907
Stock-based compensation expense	2,776	2,488
Amortization of deferred financing costs	3,852	4,158
Provision for bad debts	771	808
Noncash interest and accretion expense	5,866	5,688
Change in fair value related to equity issuance	0	(2,670)
Revision to contract termination charge	(20,478)	0
Unrealized foreign currency loss	3,879	1,571
Other, net	195	660
Changes in operating assets and liabilities:
Accounts receivable	(3,652)	(823)
Inventory	(624)	(622)
Prepaid expenses and other current assets	(2,368)	(990)
Other assets	(3,765)	(792)
Accounts payable and accrued expenses	4,288	529
Payables to affiliates	61	(5)
Other non-current liabilities	(855)	24
Deferred revenue	1,979	2,651
Net cash provided by operating activities	7,805	6,256
Cash flows used in investing activities:
Second-generation network costs (including interest)	(4,277)	(6,530)
Property and equipment additions	(3,221)	(2,116)
Purchase of intangible assets	(1,401)	(2,044)
Net cash used in investing activities	(8,899)	(10,690)
Cash flows provided by (used in) financing activities:
Principal payments of the Facility Agreement	(38,933)	(21,695)
Proceeds from Thermo Common Stock Purchase Agreement	0	33,000
Payment of debt restructuring fee	0	(20,795)
Payment of debt amendment fee	0	(255)
Proceeds from issuance of stock to Terrapin	0	12,000
Proceeds from issuance of common stock and exercise of options and warrants	319	635
Net cash provided by (used in) financing activities	(38,614)	2,890
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(73)	84
Net increase (decrease) in cash, cash equivalents and restricted cash	(39,781)	(1,460)
Cash, cash equivalents and restricted cash, beginning of period	105,279	48,213
Cash, cash equivalents and restricted cash, end of period	65,498	46,753
Reconciliation of cash, cash equivalents and restricted cash
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	105,279	48,213
Supplemental disclosure of cash flow information:
Cash paid for interest	12,070	11,659
Supplemental disclosure of non-cash financing and investing activities:
Increase in capitalized accrued interest for second-generation network costs	1,954	2,003
Capitalized accretion of debt discount and amortization of prepaid financing costs	1,854	2,510
Issuance of common stock for legal settlement	$ 0	$ 453