Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities:
Net loss	$ (51,196)	$ (47,844)
Depreciation	325	248
Accretion of debt discount	297	400
Amortization of intangible assets	728	728
Derivative liability	100
Stock-based compensation expense	11,600	12,703
Changes in assets and liabilities:
Accounts receivable	(601)	1,734
Inventories	(1,460)	(59)
Prepaid expenses and other assets	(537)	(727)
Accounts payable and accrued expenses	(662)	477
Deferred revenue	47	(377)
Net cash flows from operating activities	(41,359)	(32,717)
Investing activities:
Purchase of equipment	(316)	(619)
Net cash flows from investing activities	(316)	(619)
Financing activities:
Equity financing costs	40	(40)
Proceeds from exercise of stock options	297	480
Proceeds from issuance of common stock	2,460
Proceeds from exercise of common stock warrants		1
Payment on note payable		(3,335)
Proceeds from notes payable		20,667
Payment of deferred financing fees		(486)
Return of short swing profits		6
Net cash flows from financing activities	2,797	17,293
Net change in cash and cash equivalents	(38,878)	(16,043)
Cash and cash equivalents at beginning of year	83,560	70,472
Cash and cash equivalents at end of period	44,682	54,429
Cash paid for interest	$ 2,045	$ 1,201