Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (64,757)	$ (79,714)	$ (66,400)
Adjustments to reconcile net loss to net cash used in operating activities:
Deferred income taxes	(4,950)	(57)	(696)
Bad debt expense	534	552	(235)
Depreciation and amortization	6,890	7,982	9,111
Stock-based compensation	10,849	11,030	11,644
Change in fair value of derivative liabilities	(17,713)	(12,097)	0
Change in fair value of contingent consideration related to acquisition	(1,700)	(7,100)	(2,900)
Accretion of interest and amortization of deferred financing costs	14,264	11,801	10,165
Payable in kind interest expense on term loan facility	7,978	3,084	0
Loss on debt extinguishment	11,756	2,270	6,512
Loss on disposal of assets	0	64	0
Non-cash foreign exchange loss (gain)	(330)	711	(678)
Non-cash lease expense	260	0	0
Changes in operating assets and liabilities:
Accounts receivable and other receivables	(2,180)	10,913	4,771
Inventories	3,623	13,805	(3,035)
Prepaid expenses and other current assets	1,121	1,693	(1,034)
Accounts payable	3,107	(1,350)	(1,826)
Accrued payroll	3,624	(350)	(5,176)
Accrued expenses and other liabilities	(1,946)	(1,850)	4,374
Net cash used in operating activities	(29,570)	(38,613)	(35,403)
Cash flows from investing activities:
Maturities of marketable securities	0	0	21,000
Purchases of property and equipment	(455)	(602)	(1,170)
Net cash (used in) provided by investing activities	(455)	(602)	19,830
Cash flows from financing activities:
Cash paid for debt extinguishment	0	(1,310)	(2,515)
Net (payments) proceeds from revolving line of credit	0	(21)	21
Deferred financing costs	(3,977)	(391)	(6,755)
Proceeds from sale of common stock under employee stock purchase plan	346	1,346	2,519
Proceeds from common stock offering and pre-paid warrants, net of expenses paid	51,985	20,000	0
Proceeds from the sale of at-the-market shares	0	1,829	0
Proceeds from exercise of stock options	0	892	546
Proceeds from issuance of debt	0	0	120,000
Repayment of debt	0	(18,278)	(66,613)
Minimum tax withholding paid on behalf of employees for stock-based compensation	(209)	(390)	0
Net cash provided by financing activities	48,145	3,677	47,203
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(91)	(330)	848
Net (decrease) increase in cash, cash equivalents and restricted cash	18,029	(35,868)	32,478
Cash, cash equivalents and restricted cash, beginning of year	24,731	60,599	28,121
Cash, cash equivalents and restricted cash, end of year	42,760	24,731	60,599
Supplemental disclosure of cash flow information:
Cash paid for interest	10,321	12,499	9,836
Cash paid for income taxes	156	272	681
Cash paid for amounts included in the measurement of operating lease liabilities	3,402	0	0
Non-cash investing and financing activities:
Acquisition of property and equipment included in accounts payable	102	53	0
Fair value of embedded derivative issued in connection with loan agreements (Note 6)	20,447	15,655	0
Conversion of debt to equity	3,289	0	0
Fair value of warrants issued in connection with loan agreements (Note 6)	0	10,396	14,704
Conversion of refund to note payable (Note 6)	$ 0	$ 4,281	$ 0