Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (43,643)	$ (37,606)
Adjustments to reconcile net loss to net cash used in operating activities:
Bad debt expense	149	(89)
Depreciation and amortization	3,931	4,645
Stock-based compensation	7,286	6,188
Change in fair value of contingent consideration related to acquisition	700	(2,600)
Accretion of interest & amortization of deferred financing costs on debt	5,270	5,004
Non-cash foreign exchange (gain) loss	331	(206)
Loss on debt extinguishment	2,270	6,512
Changes in operating assets and liabilities:
Accounts receivable and other receivables	(548)	3,470
Inventories	1,753	(2,174)
Prepaid expenses and other current assets	1,664	(762)
Accounts payable	809	(3,486)
Accrued payroll	(1,542)	(3,220)
Accrued expenses and other liabilities	(1,011)	(1,092)
Net cash used in operating activities	(22,581)	(25,416)
Cash flows from investing activities:
Maturities of marketable securities	0	11,000
Purchases of property and equipment	(411)	(833)
Net cash (used in) provided by investing activities	(411)	10,167
Cash flows from financing activities:
Cash paid for debt extinguishment	(1,310)	(2,515)
Net proceeds from revolving line of credit	(21)	24,297
Deferred financing costs	0	(6,285)
Proceeds from sale of common stock under employee stock purchase plan	997	1,681
Proceeds from issuance of debt	0	120,000
Repayment of debt	0	(66,613)
Minimum tax withholding paid on behalf of employees for restricted stock units and stock options	(290)	0
Proceeds from exercise of stock options	892	449
Net cash (used in) provided by financing activities	268	71,014
Effect of exchange rate changes on cash and cash equivalents and restricted cash	(236)	632
Net (decrease) increase in cash and cash equivalents and restricted cash	(22,960)	56,397
Cash, cash equivalents and restricted cash, beginning of period	60,599	28,121
Cash, cash equivalents and restricted cash, end of period	37,639	84,518
Restricted cash, beginning of period	2,608	2,001
Cash and cash equivalents, beginning of period	57,991	26,120
Restricted cash, end of period	2,010	2,877
Cash and cash equivalents, end of period	35,629	81,641
Supplemental disclosure of cash flow information:
Cash paid for interest	6,405	2,956
Cash paid for income taxes	176	565
Non-cash investing and financing activities:
Acquisition of property and equipment included in accounts payable	10	26
Fair value of warrants issued in connection with the Facility Agreement	$ 0	$ 14,704