Income Taxes (Tables)

12 Months Ended

Dec. 31, 2013

Income Tax Disclosure [Abstract]

Schedule of loss before income taxes, domestic and foreign

The Company's loss before provision for income taxes was as follows (in thousands):

	Years Ended December 31,
	2013			2012			2011
United States	$	(41,696	)	$	(30,743	)	$	(17,474	)
Foreign	306			156			1,165
Loss before provision for income taxes	$	(41,390	)	$	(30,587	)	$	(16,309	)

Components of provision for income taxes

The components of the provision for income taxes are as follows (in thousands):

	Years Ended December 31,
	2013			2012			2011
Current provision (benefit):
Federal	$	—		$	—		$	3
State	5			7			7
Foreign	(45		)	178			82
Total current provision	(40		)	185			92
Deferred provision (benefit):
Federal	(59		)	(62		)	—
State	(7		)	(7		)	—
Foreign	19			154			149
Total deferred provision	(47		)	85			149
Total provision for (benefit from) income taxes	$	(87	)	$	270		$	241

Reconciliation of provision for income taxes calculated at the statutory rate to provision for income taxes

Reconciliation of the provision for income taxes calculated at the statutory rate to the Company's provision for (benefit from) income taxes is as follows (in thousands):

	Years Ended December 31,
	2013			2012			2011
Tax benefit at federal statutory rate	$	(14,073	)	$	(10,399	)	$	(5,708	)
State taxes	(1,948		)	(1,063		)	(1,421		)
Research and development credits	(195		)	—			(83		)
Foreign operations taxed at different rates	(108		)	7			(252		)
Stock-based compensation	117			312			1,241
Other nondeductible items	(1,272		)	204			650
Change in federal statutory rate	—			1,493			—
Change in valuation allowance	17,392			9,716			5,814
Provision for (benefit from) income taxes	$	(87	)	$	270		$	241

Significant components of our deferred tax assets and liabilities

Significant components of the Company's deferred tax assets and liabilities are as follows (in thousands):

	December 31,
	2013			2012
Deferred tax assets:
Net operating losses	$	67,507		$	54,923
Credits	4,194			3,329
Deferred revenues	1,198			1,297
Stock-based compensation	3,043			4,464
Reserves and accruals	3,626			2,090
Depreciation	2,247			1,746
Intangible assets	4,208			3,556
Unrealized gain/loss	112			166
Other assets	159			141
Total deferred tax assets:	86,294			71,712
Deferred tax liabilities:
Other	—			—
Total deferred tax liabilities:	—			—
Valuation allowance	(86,294		)	(71,692		)
Net deferred tax assets	$	—		$	20

Summary of federal, state and foreign NOL carryforwards and federal research and development tax credits

The following table sets forth the Company's federal, state and foreign NOL carryforwards and federal research and development tax credits as of December 31, 2013 (in thousands):

	December 31, 2013
	Amount		Expiration Years
Net operating losses, federal	$	184,818	2022-2033
Net operating losses, state	148,325		2015-2033
Tax credits, federal	5,138		2022-2033
Tax credits, state	5,459		Do not expire
Net operating losses, foreign	15,403		Various
Tax credits, foreign	$	16	Various

Reconciliation of the beginning and ending amount of unrecognized tax benefits

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

	December 31,
	2013			2012			2011
Balance at beginning of year	$	7,420		$	6,611		$	6,492
Additions based on tax positions related to current year	1,116			709			470
Additions to tax provision of prior years	6			263			4
Reductions to tax provision of prior years	(78		)	24			(262		)
Lapse of the applicable statute of limitations	(158		)	(187		)	(93		)
Balance at end of year	$	8,306		$	7,420		$	6,611