Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net loss	$ (17,381)us-gaap_NetIncomeLoss	$ (30,324)us-gaap_NetIncomeLoss	$ (51,868)us-gaap_NetIncomeLoss
Adjustments to reconcile net loss to net cash used in operating activities:
Stock option compensation expense	391us-gaap_StockOptionPlanExpense	174us-gaap_StockOptionPlanExpense	2,807us-gaap_StockOptionPlanExpense
Restricted stock compensation expense	100us-gaap_RestrictedStockExpense	117us-gaap_RestrictedStockExpense	1,018us-gaap_RestrictedStockExpense
Depreciation expense	958us-gaap_Depreciation	1,126us-gaap_Depreciation	1,331us-gaap_Depreciation
Provision for inventory obsolescence	118	0	0
Loss on disposal of equipment	282	5	0
Warrant liability fair value adjustment	(1,942)us-gaap_FairValueAdjustmentOfWarrants	(2,756)us-gaap_FairValueAdjustmentOfWarrants	(2,159)us-gaap_FairValueAdjustmentOfWarrants
Non-cash interest income	0us-gaap_OtherNoncashIncome	(1)us-gaap_OtherNoncashIncome	2us-gaap_OtherNoncashIncome
Changes in assets and liabilities:
Decrease (increase) in prepaid expenses and other current assets	718	(235)	(228)
Decrease (increase) in accounts receivable	161	(211)	(144)
Decrease (increase) in inventories	237us-gaap_IncreaseDecreaseInInventories	391us-gaap_IncreaseDecreaseInInventories	(1,105)us-gaap_IncreaseDecreaseInInventories
Increase (decrease) in accounts payable and accrued expenses	132	(2,445)	331
Increase in other non-current liabilities	674	57	9
Net cash used in operating activities	(15,552)	(34,102)	(50,006)
Cash flows from investing activities:
Purchase of property, plant, and equipment	(44)	(142)	(2,120)
Proceeds from sales of property, plant and equipment	37	0	0
Proceeds from maturities of short-term investments	0	0	4,980
Net cash (used in) provided by investing activities	(7)	(142)	2,860
Cash flows from financing activities:
Net proceeds from sale of stock and exercise of stock options and warrants	4,869	41,702	45,058
Net cash provided by financing activities	4,869	41,702	45,058
Foreign currency effects on cash	(90)	65	37
(Decrease) increase in cash and cash equivalents	(10,780)	7,523	(2,051)
Cash and cash equivalents at beginning of period	31,249	23,726	25,777
Cash and cash equivalents at end of period	20,469	31,249	23,726
Supplemental non-cash activities:
Fair value of warrants issued	0	1,857	4,055
Fair value of warrants exercised	$ 143	$ 218	$ 908

The amount of recurring noncash expense charge against earnings in the period that reflects the allocation of capitalized costs associated with the organization of the company and the gains (losses) included in results of operations resulting from the sale or disposal of property, plant and equipment, which do not qualify for treatment as discontinued operations.

No definition available.