Condensed Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating activities
Net (loss) income	$ (4,202)	$ 5,284
Adjustments to reconcile net (loss) income to net cash used for operating activities:
Share-based compensation expense	3,530
Gain on adjustment to fair value of derivative liabilities		(5,954)
Changes in operating assets and liabilities:
Restricted cash	(37)
Prepaids and other current assets	(51)	10
Accounts payable and accrued expenses	46	1
Accrued payroll and related expenses	9
Net cash used for operating activities	(705)	(659)
Net decrease in cash and cash equivalents	(705)	(659)
Cash and cash equivalents at beginning of period	3,405	5,040
Cash, cash equivalents at end of period	2,700	4,381
Supplemental disclosure of cash flow information:
Conversion of series C-12 and D-12 preferred into common stock	$ 20