CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash Flows from Operating Activities:
Net Loss	$ (27,289)	$ (20,295)
Adjustments to Reconcile Net Loss to Net Cash Used in Operating Activities:
Depreciation and Amortization	1,073	1,130
Amortization of Intangible Assets	583	966
Amortization and Premium of Marketable Securities	(157)	(242)
Realized (Gain) Loss on Sales and Maturities of Marketable Securities	(6)	8
Gain on Sale or Disposal of Assets	(12)	(55)
Stock-Based Compensation Expense	1,088	1,133
Non-Cash Interest Expense	111	192
Changes in Operating Assets and Liabilities:
Accounts and Other Receivables	109	161
Prepaid and Other Current Assets	(493)	(408)
Other Assets	(99)	(4)
Accounts Payable and Accrued Expenses	(993)	(937)
Other Liabilities	573	122
Net Cash Used in Operating Activities	(25,512)	(18,229)
Cash Flows from Investing Activities:
Sales and Maturities of Marketable Securities	20,919	18,394
Purchases of Marketable Securities	(39,383)	(38,727)
Acquisition of Property and Equipment	(122)	(282)
Proceeds from Sale or Disposal of Assets	156	64
Net Cash Used in Investing Activities	(18,430)	(20,551)
Cash Flows from Financing Activities:
Net Proceeds from Stock Issuances	51,957	35,889
(Payments) Issuance of Term Loan	(1,323)	5,000
Payment of Convertible Subordinated Debt		(12,503)
Payments of Other Liabilities	(29)	(58)
Net Cash Provided by Financing Activities	50,605	28,328
Effect of Exchange Rate Changes on Cash and Cash Equivalents	1	(5)
Net Increase (Decrease) in Cash and Cash Equivalents	6,664	(10,457)
Cash and Cash Equivalents at Beginning of Period	11,899	21,287
Cash and Cash Equivalents at End of Period	$ 18,563	$ 10,830