Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net loss	$ (30,324)	$ (51,868)	$ (30,885)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock option compensation expense	174	2,807	3,605
Restricted stock compensation expense	117	1,018	654
Depreciation expense	1,126	1,331	1,035
Loss on disposal of equipment	5	0	0
Warrant liability fair value adjustment	(2,756)	(2,159)	(15,566)
Non-cash interest income	(1)	2	0
Changes in assets and liabilities:
Decrease (increase) in prepaid expenses and other current assets	(235)	(228)	553
Decrease in investment in common stock	0	0	26
Decrease (increase) in accounts receivable	(211)	(144)	0
Decrease (increase) in inventories	391	(1,105)	0
Increase (decrease) in accounts payable and accrued expenses	(2,445)	331	3,206
Increase in deferred revenue and long-term accrued expenses	57	9	0
Net cash used in operating activities	(34,102)	(50,006)	(37,372)
Cash flows from investing activities:
Purchase of property, plant, and equipment	(142)	(2,120)	(2,607)
Purchase of short-term investments and marketable equity securities	0	0	(4,980)
Proceeds from maturities of short-term investments	0	4,980	1,492
Net cash (used in) provided by investing activities	(142)	2,860	(6,095)
Cash flows from financing activities:
Net proceeds from sale of stock and exercise of stock options and warrants	41,702	45,058	23,623
Net cash provided by financing activities	41,702	45,058	23,623
Foreign currency effects on cash	65	37	0
(Decrease) increase in cash and cash equivalents	7,523	(2,051)	(19,844)
Cash and cash equivalents at beginning of period	23,726	25,777	45,621
Cash and cash equivalents at end of period	31,249	23,726	25,777
Supplemental non-cash activities:
Cashless exercise of stock options and shares surrendered upon restricted stock vesting	0	0	(61)
Fair value of warrants issued	(1,857)	4,055	0
Fair value of warrants reclassified from liability to additional paid-in capital upon exercise	$ 218	$ 908	$ 0

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.