Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended			389 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012
Cash flows from operating activities:
Net loss	$ (121,287)	$ (2,318)	$ (32,177)	$ (431,251)
Adjustments to reconcile net loss to net cash flows used in operating activities:
Depreciation and amortization	1,525	1,300	1,463	21,970
Loss on disposal of assets	357	190	776	2,636
Realized gain on sale of short-term securities-available-for-sale	0	0	0	(3,863)
Write-down of short-term securities-available-for-sale	0	0	0	17,001
Impairment charge on real estate owned	0	109	408	1,445
Stock-based compensation	3,078	3,129	3,169	32,073
Acquired in-process research and development	0	0	0	29,461
Increase (decrease) on warrant valuation	91,938	(33,022)	11,502	66,968
Net increase in accounts receivable and other assets	(3,587)	(1,063)	(1,211)	(8,761)
Net increase (decrease) in accounts payable, accrued employee compensation, and other liabilities	(1,718)	7,996	861	12,413
Net cash used in operating activities	(29,694)	(23,679)	(15,209)	(259,908)
Cash flows from investing activities:
Purchase of property and equipment	(108)	(1,178)	(832)	(19,987)
Patent costs	(1,037)	(1,127)	(1,122)	(10,529)
Purchase of marketable securities	0	0	(7)	(112,993)
Sale of marketable securities	0	0	0	117,724
Acquisition costs	0	0	0	(2,389)
Net cash used in investing activities	(1,145)	(2,305)	(1,961)	(28,174)
Cash flows from financing activities:
Proceeds from sale of common stock, warrants, and partnership units, net of offering costs, and exercise of options and warrants	178,681	32,380	2,561	476,559
Repayments of long-term debt	(85)	(81)	(77)	(430)
Other financing activities, net	0	0	0	(386)
Net cash provided by financing activities	178,596	32,299	2,484	475,743
Increase (decrease) in cash and cash equivalents	147,757	6,315	(14,686)	187,661
Cash and cash equivalents:
Beginning of period	39,904	33,589	48,275	0
End of period	187,661	39,904	33,589	187,661
Supplemental Disclosure of Cash Flow Information:
Cash paid during the year for interest	86	90	94	575
Supplemental Schedule of Noncash Investing Activities and Financing Activities:
Short-term securities-available-for-sale received in connection with the private offering	0	0	0	17,897
Issuance of common stock in satisfaction of warrants and other liabilities	32,191	643	0	32,834
Issuance of common stock for building purchase	0	0	0	750
Assumption of long-term debt for building purchase	0	0	0	2,200
Issuance of common stock to acquire assets	0	0	0	8,075
Assumption of liabilities to acquire assets	$ 0	$ 0	$ 0	$ 2,124