Consolidated Statements of Cash Flows (Unaudited) - USD ($) shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating Activities
Net loss	$ (33,369)	$ (29,573)
Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities:
Depreciation and amortization	1,391	936
Amortization of debt discount and debt issuance costs	89	57
Stock-based compensation	2,388	2,018
Loss on disposal of property and equipment	34	5
Deferred tax benefit	(99)
Changes in operating assets and liabilities, net of effect of acquisition:
Accounts receivable	133	150
Interest receivable	(5)	68
Inventories	(250)	434
Other current and long term assets	(248)	(241)
Restricted cash	250	125
Accounts payable	984	1,461
Accrued expenses	4,127	350
Net cash and cash equivalents used in operating activities	(24,575)	(24,210)
Investing Activities
Proceeds from sale and maturities of investments		6,191
Proceeds from sale of property and equipment		25
Payments for acquisition	(25,000)
Purchase of property and equipment	(728)	(1,626)
Net cash and cash equivalents (used in) provided by investing activities	(25,728)	4,590
Financing Activities
Payment of debt		(2,877)
Proceeds from issuance of common stock, net of issuance costs	58,295	52,433
Proceeds from issuance of debt, net of debt discount	9,886	4,321
Taxes paid related to net share settlement of vesting of restricted stock units	(3)
Proceeds from exercise of stock options and warrants	252	73
Net cash and cash equivalents provided by financing activities	68,430	53,950
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase in cash and cash equivalents	18,127	34,330
Cash and Cash Equivalents, beginning of period	34,766	10,014
Cash and Cash Equivalents, end of period	52,893	44,344
Supplemental Disclosure for Cash Flow Information
Interest paid	$ 598	$ 518
Supplemental Schedule of Noncash Investing and Financing Activities
Issuance of common stock warrants	96	54
Contingent consideration related to acquisition	$ 24,300
Issuance of common stock related to acquisition	$ 43,677