CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net loss	$ (3,614)	$ (12,635)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,081	2,492
Gain on extinguishment of debt	(977)
Accretion of interest on long-term payment obligation	277	335
Amortization of debt issuance costs	617	633
Stock-based compensation expense	1,916	2,245
Loss on disposal of fixed assets		329
Changes in operating assets and liabilities:
Accounts receivable	(1,197)	(1,166)
Inventories	(1,785)	2,741
Prepaid expenses and other assets	(992)	(182)
Accounts payable	1,531	154
Payment obligation liability	(892)	(925)
Deferred revenue	58	(370)
Accrued expenses and other liabilities	(2,087)	155
Net cash used in operating activities	(5,064)	(6,194)
Cash flows from investing activities:
Capital expenditures	(686)	(425)
Net cash used in investing activities	(686)	(425)
Cash flows from financing activities:
Proceeds from issuance of debt, net of issuance costs	42,735
Repayments of debt	(42,805)
Sale of common stock, net of issuance costs	12,560
Taxes paid related to net share settlement of restricted stock units	(594)	(180)
Net cash provided by (used in) financing activities	11,896	(180)
Effect of exchange rates on cash	479	(685)
Net increase (decrease) in cash	6,625	(7,484)
Cash at beginning of period	9,116	16,667
Cash at end of period	15,741	9,183
Supplemental Disclosures of Cash Flow Information
Interest paid	1,379	1,181
Taxes paid, net	96	158
Non-cash investing and financing activities:
Warrants issued as debt issuance costs in connection with debt agreements	2,319	376
Liability to be settled in common stock	$ 250
Property and equipment included in accruals		83
Restricted Stock Units (RSUs)
Non-cash investing and financing activities:
Restricted stock units issued to settle liability		$ 387