CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash Flows from Operating Activities:
Net Loss	$ (13,516)	$ (10,059)
Adjustments to Reconcile Net Loss to Net Cash Used in Operating Activities:
Depreciation and Amortization	544	562
Amortization of Intangible Assets	291	483
Amortization and Premium of Marketable Securities	(373)	244
Realized (Gain) Loss on Sales and Maturities of Marketable Securities	(4)	5
Loss (Gain) on Sales or Disposal of Assets	23	(55)
Stock-Based Compensation Expense	641	580
Non-Cash Interest Expense	57	135
Changes in Operating Assets and Liabilities:
Accounts and Other Receivables	30	81
Prepaid and Other Current Assets	(672)	(162)
Other Assets	(131)	(37)
Accounts Payable and Accrued Expenses	(1,049)	(929)
Other Liabilities	606	288
Net Cash Used in Operating Activities	(13,553)	(8,864)
Cash Flows from Investing Activities:
Sales and Maturities of Marketable Securities	5,912	8,653
Purchases of Marketable Securities	(33,388)	(3,245)
Acquisition of Property and Equipment	(42)	(202)
Proceeds from Sales or Disposal of Assets	11	64
Net Cash (Used in) Provided by Investing Activities	(27,507)	5,270
Cash Flows from Financing Activities:
Net Proceeds from Stock Issuances	51,929
Issuance of Term Loan		5,000
Payment of Convertible Subordinated Debt		(12,503)
Payments of Other Liabilities	(15)	(46)
Net Cash Provided by (Used in) Financing Activities	51,914	(7,549)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	2	(4)
Net Increase (Decrease) in Cash and Cash Equivalents	10,856	(11,147)
Cash and Cash Equivalents at Beginning of Period	11,899	21,287
Cash and Cash Equivalents at End of Period	$ 22,755	$ 10,140