Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating Activities
Net loss	$ (30,066)	$ (49,477)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain from change in fair value of derivative warrant liability	6,772
Gain from change in fair value of embedded derivative of 2022 note	(3,470)	(2,280)
Gain from change in fair value of 2017 note	(544)
Non-cash stock-based compensation	2,362	3,083
Depreciation and amortization	3,214	2,558
Non-cash interest expense	6,374	3,747
Loss on conversion of debt		2,038
Loss from change in fair value of derivatives		175
Other non-cash expenses		649
Changes in operating assets and liabilities:
Accounts receivable	(685)	(169)
Inventories	(446)	1,814
Prepaid expenses and other current assets	302	239
Deposits and other assets		(49)
Accounts payable, accrued expenses, and long-term liabilities	(2,875)	5,952
Net cash used in operating activities	(32,606)	(31,720)
Investing Activities
Acquisitions of property, plant and equipment	(4,553)	(4,524)
Proceeds from sales tax refund		1,896
Restricted deposits	(2,611)
Net cash used in investing activities	(7,164)	(2,628)
Financing Activities
Payments on secured debt	(9,720)	(6,715)
Debt and equity offering costs	(5,051)
Proceeds from issuance of common stock upon exercise of stock options and employee stock purchase plan	19	59
Proceeds from issuance of common stock and common stock units	18,000
Proceeds from issuance of 2017 Notes	25,907
Deposit on secured debt and other		(79)
Net cash (used in) provided by financing activities	29,155	(6,735)
Net (decrease) increase in cash and cash equivalents	(10,615)	(41,083)
Cash and cash equivalents
Beginning of period	24,625	66,744
Ending of period	14,010	25,661
Supplemental disclosures of cash and non-cash investing and financing transactions
Cash paid for interest, net of interest capitalized	3,697	3,805
Capitalization of interest, from 2017 Convertible Notes	201
Non-cash purchase of property, plant and equipment	99	5,875
Issuance of common stock for services		483
Issuance of common stock warrants	2,400
Common Stock
Supplemental disclosures of cash and non-cash investing and financing transactions
Conversion of convertible debt to common stock		$ 12,784