CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash Flows From Operating Activities:
Net Loss	$ (59,123)	$ (44,799)	$ (2,533)
Adjustments to Reconcile Net Loss to Cash Used in Operating Activities:
Depreciation and Amortization	2,047	2,248	2,718
Amortization of Intangible Assets	1,090	1,913	3,143
Amortization and Premium of Marketable Securities	(660)	17	(14)
Realized (Gain) Loss on Sales and Maturities of Marketable Securities	(6)	5	(4)
Gain on Sale or Disposal of Assets	(74)	(58)	(38)
Stock-Based Compensation Expense	2,298	2,342	2,802
Non-Cash Interest Expense	226	307	728
Changes in Operating Assets and Liabilities:
Accounts and Other Receivables	126	154	220
Prepaid and Other Current Assets	33	241	(546)
Other Assets	(95)	34	5,592
Accounts Payable and Accrued Expenses	3,762	2,076	(1,193)
Deferred Revenue			(39,382)
Other Liabilities	594	(138)	(1,865)
Net Cash Used in Operating Activities	(49,782)	(35,658)	(30,372)
Cash Flows From Investing Activities:
Sales and Maturities of Marketable Securities	52,360	51,003	42,383
Purchases of Marketable Securities	(69,255)	(52,717)	(56,522)
Acquisition of Property and Equipment	(303)	(509)	(2,100)
Proceeds from Sale or Disposal of Assets	218	68	77
Net Cash Used in Investing Activities	(16,980)	(2,155)	(16,162)
Cash Flows From Financing Activities:
Net Proceeds from Stock Issuances	83,784	36,023	1,014
(Payments) Issuance of Term Loan	(3,971)	5,000	10,000
Payment of Convertible Subordinated Debt		(12,503)
Payment of Other Liabilities	(55)	(86)	(197)
Net Cash Provided by Financing Activities	79,758	28,434	10,817
Effect of Exchange Rate Changes on Cash and Cash Equivalents	2	(9)	2
Net Increase (Decrease) in Cash and Cash Equivalents	12,998	(9,388)	(35,715)
Cash and Cash Equivalents at Beginning of Period	11,899	21,287	57,002
Cash and Cash Equivalents at End of Period	24,897	11,899	21,287
Supplemental Disclosure of Cash Flow Information
Cash Paid for Interest	$ 1,384	$ 1,560	$ 604