CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash Flows from Operating Activities:
Net Loss	$ (20,295)	$ (16,107)
Adjustments to Reconcile Net Loss to Net Cash Used in Operating Activities:
Depreciation and Amortization	1,130	1,608
Amortization of Intangible Assets	966	2,178
Amortization and Premium of Marketable Securities	(242)	(520)
Realized Loss on Sales and Maturities of Marketable Securities	8	31
(Gain) Loss on Sale or Disposal of Assets	(55)	38
Stock-Based Compensation Expense	1,133	1,614
Non-Cash Interest Expense	192	364
Changes in Operating Assets and Liabilities:
Accounts and Other Receivables	161	(194)
Prepaid and Other Current Assets	(408)	(702)
Other Assets	(4)	373
Accounts Payable and Accrued Expenses	(937)	(1,853)
Deferred Revenue		(2,040)
Other Long-Term Liabilities	122	(1,405)
Net Cash Used in Operating Activities	(18,229)	(16,615)
Cash Flows from Investing Activities:
Sales and Maturities of Marketable Securities	18,394	19,252
Purchases of Marketable Securities	(38,727)	(43,875)
Acquisition of Property and Equipment	(282)	(1,129)
Proceeds from Sale or Disposal of Assets	64
Net Cash Used in Investing Activities	(20,551)	(25,752)
Cash Flows from Financing Activities:
Net Proceeds from Stock Issuances	35,889	616
Issuance of Term Loan	5,000
Payment of Convertible Subordinated Debt	(12,503)
Payments of Other Long-Term Liabilities	(58)	(94)
Net Cash Provided by Financing Activities	28,328	522
Effect of Exchange Rate Changes on Cash and Cash Equivalents	(5)	1
Net Decrease in Cash and Cash Equivalents	(10,457)	(41,844)
Cash and Cash Equivalents at Beginning of Period	21,287	57,002
Cash and Cash Equivalents at End of Period	$ 10,830	$ 15,158