CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net income (loss)	$ (123,603)	$ 85,248	$ (80,008)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation, amortization and impairments	4,614	6,147	4,219
Accretion of discount on marketable securities			(20)
Stock-based compensation	7,675	4,836	4,355
Deferred executive compensation expense	1,719	1,477	1,134
Revaluation of warrant liability	46,715	19,532	7,804
Increase (decrease) from:
Other current and non-current assets	(145)	814	2,092
Amounts due under license and collaboration agreements	373	3,176	1,997
Accounts payable	2,394	(1,684)	(4,564)
Accrued compensation and benefits	82	76	233
Accrued product development expenses	3,759	117	(1,864)
Other accrued expenses	1,271	(1,043)	(1,282)
Other liabilities	1,660	18	662
Deferred revenue	999	(111,611)	14,347
Deferred executive compensation paid	(775)	(685)	(1,009)
Net cash provided by (used in) operating activities	(53,262)	6,418	(51,904)
Cash flows from investing activities:
Acquisitions of marketable securities			(7,599)
Proceeds from maturities of marketable securities			22,426
Change in restricted cash			(50)
Investment in property and equipment	(1,452)	(1,344)	(2,198)
Investment in intangible assets	(671)	(691)	(1,308)
Net cash provided by (used in) investing activities	(2,123)	(2,035)	11,271
Cash flows from financing activities:
Proceeds from long-term borrowings	4,375
Repayment of long-term borrowings	(1,400)	(1,925)	(1,400)
Proceeds from issuance of common stock, net of issuance costs	243,058	57,515	58,370
Proceeds from issuance of common stock pursuant to warrants	8,080	2,624
Principal payments under capital lease obligations	(66)	(118)	(87)
Payment of tax withholding obligations related to stock compensation	(827)
Proceeds from issuance of common stock pursuant to stock option and purchase plans	4,791	789	568
Net cash provided by financing activities	258,011	58,885	57,451
Net increase in cash and cash equivalents	202,626	63,268	16,818
Cash and cash equivalents, beginning of year	103,630	40,362	23,544
Cash and cash equivalents, end of year	306,256	103,630	40,362
Supplemental disclosures:
Interest paid	230	182	302
Property and equipment acquired through capital lease		19	206
Non-cash transaction - property and equipment included in accounts payable or accruals	$ 911