CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash Flows from Operating Activities:
Net Loss	$ (42,316)	$ (32,067)
Adjustments to Reconcile Net Loss to Net Cash Used in Operating Activities:
Depreciation and Amortization	1,576	1,696
Amortization of Intangible Assets	836	1,622
Amortization and Premium of Marketable Securities	(420)	(96)
Realized (Gain) Loss on Sales and Maturities of Marketable Securities	(6)	5
Gain on Sale or Disposal of Assets	(74)	(58)
Stock-Based Compensation Expense	1,614	1,703
Non-Cash Interest Expense	169	250
Changes in Operating Assets and Liabilities:
Accounts and Other Receivables	138	120
Prepaid and Other Current Assets	(8)	58
Other Assets	(80)	15
Accounts Payable and Accrued Expenses	1,495	556
Other Liabilities	620	(92)
Net Cash Used in Operating Activities	(36,456)	(26,288)
Cash Flows from Investing Activities:
Sales and Maturities of Marketable Securities	45,432	38,353
Purchases of Marketable Securities	(57,900)	(48,217)
Acquisition of Property and Equipment	(193)	(403)
Proceeds from Sale or Disposal of Assets	218	68
Net Cash Used in Investing Activities	(12,443)	(10,199)
Cash Flows from Financing Activities:
Net Proceeds from Stock Issuances	62,872	35,880
(Payments) Issuance of Term Loan	(2,646)	5,000
Payment of Convertible Subordinated Debt		(12,503)
Payments of Other Liabilities	(41)	(72)
Net Cash Provided by Financing Activities	60,185	28,305
Effect of Exchange Rate Changes on Cash and Cash Equivalents	2	(8)
Net Increase (Decrease) in Cash and Cash Equivalents	11,288	(8,190)
Cash and Cash Equivalents at Beginning of Period	11,899	21,287
Cash and Cash Equivalents at End of Period	$ 23,187	$ 13,097