Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flow from operating activities:
Net loss	$ (22,099)	$ (21,263)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	371	364
Provision for excess inventory	1,465	0
Stock-based compensation and 401(k) Plan employer match	1,975	1,489
Fair value adjustment of common stock warrants	(1,826)	(2,686)
Amortization of discount on long-term debt	909	177
Changes in:
Inventory	(2,196)	159
Accounts receivable	26	0
Prepaid expenses and other current assets	334	101
Accounts payable	74	753
Accrued expenses	1,166	580
Deferred revenue	(34)	0
Other assets	0	(107)
Other liabilities	(423)	(10)
Net cash used in operating activities	(20,258)	(20,443)
Cash flows from investing activities:
Purchase of property and equipment	(883)	(120)
Net cash used in investing activities	(883)	(120)
Cash flows from financing activities:
Proceeds from issuance of securities, net of expenses	0	15,110
Proceeds from issuance of long-term debt, net of expenses	0	9,850
Proceeds from exercise of common stock options	31	1
Proceeds from exercise of common stock warrants	423	0
Repayment of equipment loans	(39)	(37)
Net cash provided by financing activities	415	24,924
Net decrease in cash and cash equivalents	(20,726)	4,361
Cash and cash equivalents - beginning of period	86,283	26,892
Cash and cash equivalents - end of period	65,557	31,253
Supplementary disclosure of cash flows information:
Interest paid	$ 1,305	$ 336