Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income Taxes

Schedule of components of the income tax (benefit) provision

	Year Ended
	December 31,
	2014		2013		2012
Current:
Federal	$	—	$	—	$	—
State		63		7		3
Total current provision		63		7		3
Deferred:
Federal		540		504		(318)
State		37		68		(291)
Total deferred provision (benefit)		577		572		(609)
Total income tax provision (benefit)	$	640	$	579	$	(606)

Schedule of reconciliation between the amount computed by applying the U.S. federal statutory tax rate of 34% to income before income taxes and the income tax (benefit) provision

	Year Ended
	December 31,
	2014		2013		2012
Income tax benefit based on the federal statutory rate	34.0	%	34.0	%	34.0	%
State income taxes, net of federal benefit	2.0		(0.9)		7.6
Nondeductible expenses	(0.7)		(1.5)		(0.1)
Change in valuation allowance	(34.7)		(26.3)		(40.0)
Stock-based compensation	(2.0)		(8.3)		(0.9)
Other	0.1		0.6		0.2
Overall effective income tax rate	(1.3)	%	(2.4)	%	0.8	%

Schedule of components of deferred tax assets (liabilities)

	December 31,
	2014		2013
Deferred income tax assets:
Net operating loss carryforwards	$	56,957	$	49,921
Stock-based compensation		18,648		8,262
Accrued expenses		1,932		2,852
Research and development tax credits		610		610
Other		277		172
Gross deferred tax assets		78,424		61,817
Valuation allowance		(64,449)		(47,858)
Net deferred tax assets		13,975		13,959
Deferred tax liabilities:
State taxes		(3,802)		(3,296)
Property, equipment and software		(3,985)		(3,353)
Intangible assets and goodwill		(8,020)		(8,566)
Gross deferred tax liabilities		(15,807)		(15,215)
Total net deferred tax liabilities	$	(1,832)	$	(1,256)

Schedule of change in the valuation allowance

	Year Ended
	December 31,
	2014		2013		2012
Valuation allowance, at beginning of year	$	47,858	$	41,412	$	11,348
Increase in valuation allowance		16,591		6,446		30,064
Valuation allowance, at end of year	$	64,449	$	47,858	$	41,412

Schedule of reconciliation of the total amounts of unrecognized tax benefits

	Year Ended
	December 31,
	2014		2013		2012
Unrecognized tax benefit, beginning of year	$	(4)	$	(4)	$	—
Additions based on current year tax positions		21		—		610
Additions for prior years' tax positions		29		—		—
Reductions for prior years' tax positions		—		—		(614)
Unrecognized tax benefit, end of year	$	46	$	(4)	$	(4)