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	$ (55,894)	$ (37,949)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,015	946
Amortization of premium on marketable securities	7
Stock-based compensation	4,913	2,404
Deferred executive compensation expense	633	380
Revaluation of warrant liability	15,924	18,572
Increase (decrease) from:
Other current assets	(1,773)	(594)
Other assets	(22)	2
Accounts payable	616	(63)
Accrued compensation and benefits	2,649	(319)
Accrued product development expenses	(988)	(1,134)
Other accrued expenses	1,601	486
Other current liabilities	712
Deferred revenue	(57)
Deferred executive compensation paid	103
Net cash used in operating activities	(30,561)	(17,269)
Cash flows from investing activities:
Acquisitions of marketable securities	(89,554)
Investment in property and equipment	(916)	(423)
Investment in intangible assets	(195)	(241)
Net cash used in investing activities	(90,665)	(664)
Cash flows from financing activities:
Proceeds from long-term borrowings		4,375
Repayment of long-term borrowings	(350)	(350)
Principal payments under capital lease obligation	(15)	(24)
Proceeds from issuance of common stock pursuant to warrants	12,482	7,580
Payment of tax withholding obligations related to stock compensation	(2,302)	(324)
Proceeds from issuance of common stock pursuant to stock option and purchase plans	3,377	1,402
Net cash provided by financing activities	13,192	12,659
Net decrease in cash and cash equivalents	(108,034)	(5,274)
Cash and cash equivalents, beginning of period	306,256	103,630
Cash and cash equivalents, end of period	198,222	98,356
Supplemental disclosure:
Non-cash transaction - investment in property and equipment included in accounts payable or accruals	$ 758