Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net loss	$ (51,868)	$ (30,885)	$ (46,684)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock option compensation expense	2,807	3,605	3,839
Restricted stock and warrant compensation expense	1,018	654	1,675
Depreciation expense	1,331	1,035	472
Loss on disposal of equipment	0	0	7
Warrant liability fair value adjustment	(2,159)	(15,566)	15,951
Non-cash interest income	2	0	(3)
Changes in assets and liabilities:
Decrease (increase) in prepaid expenses and other current assets	(228)	553	(1,001)
Decrease in investment in common stock	0	26	10
Decrease (increase) in accounts receivable	(144)
Decrease (increase) in inventories	(1,105)	0	0
Increase (decrease) in accounts payable and accrued expenses	331	3,206	1,351
Deferred revenue	9	0	300
Net cash used in operating activities	(50,006)	(37,372)	(24,083)
Cash flows from investing activities:
Purchase of property, plant, and equipment	(2,120)	(2,607)	(1,638)
Purchase of short-term investments and marketable equity securities	0	(4,980)	(3,235)
Proceeds from maturities of short-term investments	4,980	1,492	1,743
Net cash (used in) provided by investing activities	2,860	(6,095)	(3,130)
Cash flows from financing activities:
Net proceeds from sale of stock and exercise of stock options and warrants	45,058	23,623	37,348
Net cash provided by financing activities	45,058	23,623	37,348
Foreign currency effects on cash	37	0	0
(Decrease) increase in cash and cash equivalents	(2,051)	(19,844)	10,135
Cash and cash equivalents at beginning of period	25,777	45,621	35,486
Cash and cash equivalents at end of period	23,726	25,777	45,621
Supplemental non-cash activities:
Cashless exercise of stock options and shares surrendered upon restricted stock vesting		(61)	700
Fair value of warrants issued	4,055	0	0
Fair value of warrants reclassified from liability to additional paid-in capital upon exercise	$ 908	$ 0	$ 9,154

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.