CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net (loss) income	$ (8,923)	$ (4,810)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	896	729
Accretion of interest on long-term payment obligation	105	134
Amortization of debt issuance costs	374	116
Stock-based compensation expense	937	1,242
Loss on disposal of fixed assets	326
Changes in operating assets and liabilities:
Accounts receivable	(501)	3,763
Inventories	(296)	(1,060)
Prepaid expenses and other assets	(474)	(163)
Accounts payable	(1,109)	(1,451)
Payment obligation liability	(286)	(282)
Deferred revenue	(144)	(158)
Accrued expenses and other liabilities	2,068	(959)
Net cash used in operating activities	(7,027)	(2,899)
Cash flows from investing activities:
Capital expenditures	(244)	(169)
Net cash used in investing activities	(244)	(169)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee stock purchase plan and options and warrants exercised		6
Repurchase of common stock		(606)
Net cash used in financing activities		(600)
Effect of exchange rates on cash	(441)	208
Net decrease in cash	(7,712)	(3,460)
Cash at beginning of period	16,667	36,547
Cash at end of period	8,955	33,087
Non-cash investing and financing activities:
Warrants issued as debt issuance costs in connection with debt modification	232
Common stock issued to acquire share of noncontrolling interest		1,216
Property and equipment included in accounts payable	$ 165	$ 27