Income Taxes (Tables)

12 Months Ended

Dec. 31, 2011

Income Taxes [Abstract]

Schedule Of Deferred Tax Assets

	December 31,
	2011			2010
Deferred tax assets
Net operating loss carryforwards	$	122,656		$	73,788
Deferred revenue		48,062			41,547
Capitalized research and development		21,226			26,443
Tax credit carryforwards		31,365			26,365
Share-based compensation		10,730			7,318
Depreciation and amortization		2,210			1,931
Other		8,242			5,466
Total deferred tax assets		244,491			182,858
Less: valuation allowance		(244,491	)		(182,858	)
Net deferred tax assets	$	0		$	0

Schedule Of Effective Income Tax Rate

	Years ended December 31,
	2011			2010			2009
Statutory federal income tax rate		(35	%)		(35	%)		(35	%)
Tax credits		(3	)		(6	)		(14	)
State income taxes and other		(3	)		0			(3	)
Valuation allowance		41			41			52
Effective tax rate		0	%		0	%		0	%