Income Taxes (Tables)

12 Months Ended

Dec. 31, 2013

Income Taxes

Schedule of significant components of deferred income tax assets

Significant components of the Company's deferred income tax assets as of December 31, 2013 and 2012, are as follows (in thousands):

	2013			2012
Deferred tax assets:
Net operating loss carry forwards	$	202,289		$	154,865
Research and development credit carry forwards		16,659			13,192
Stock-based compensation		15,476			9,386
Accruals and other		18,927			5,528
Depreciation		218			185
Deferred revenue		4,009			420
		257,578			183,576
Valuation allowance		(257,578	)		(183,576	)
Total	$	—		$	—

Schedule of (loss)/income from continuing operations before (benefit)/provision for income taxes

 The (benefit)/provision for income taxes is based upon (loss)/income from continuing operations before (benefit)/provision for income taxes as follows, for the years ended December 31, 2013, 2012 and 2011 (in thousands):

	2013			2012			2011
Loss before income taxes:
Domestic	$	(174,083	)	$	(138,599	)	$	(46,836	)
International		(766	)		(1,107	)		—
Loss before taxes	$	(174,849	)	$	(139,706	)	$	(46,836	)

Income Tax Disclosures

Schedule of reconciliation between the U.S. federal statutory tax rate and effective tax rate from continuing operations

	2013			2012			2011
Tax at U.S. federal statutory rate		(35	)%		(35	)%		(35	)%
Change in valuation allowance		35			34			38
Permanent items		2			1			1
Tax credits		(1	)		—			(4	)
Other		(1	)		—			—
Effective tax rate		0	%		0	%		0	%

Schedule of reconciliation of unrecognized tax benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits in 2013 and 2012, is as follows (in thousands):

	2013		2012		2011
Unrecognized tax benefits as of January 1	$	1,215	$	1,215	$	1,171
Gross increase/(decrease) for tax positions of prior years		447		—		44
Gross increase/(decrease) for tax positions of current year		—		—		—
Settlements		—		—		—
Lapse of statute of limitations		—		—		—
Unrecognized tax benefits balance at December 31	$	1,662	$	1,215	$	1,215

Schedule of unrecognized tax benefits recorded on consolidated balance sheets

The remaining balance recorded on the Company's consolidated balance sheets as of December 31, 2013 and 2012, is as follows (in thousands):

	2013			2012
Total unrecognized tax benefits	$	1,662		$	1,215
Amounts netted against deferred tax assets		(1,502	)		(1,055	)
Unrecognized tax benefits recorded on consolidated balance sheets	$	160		$	160

Continuing operations

Income Tax Disclosures

Schedule of components of (benefit)/provision for income taxes

The (benefit)/provision for income taxes consists of the following components for the years ended December 31, 2013, 2012 and 2011 (in thousands): 

	2013		2012		2011
Current
Federal	$	—	$	—	$	—
State		97		27		190
Foreign		—		—		—
Total current (benefit)/provision for income taxes	$	97	$	27	$	190
Deferred
Federal	$	—	$	—	$	—
State		—		—		—
Foreign		—		—		—
Total deferred benefit for income taxes	$	—	$	—	$	—
Total (benefit)/provision for income taxes from continuing operations	$	97	$	27	$	190