Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Schedule of Components of Income (Loss) Before Provision for (Benefit from) Income Taxes

The components of our income (loss) before provision for (benefit from) income taxes are as follows (in thousands):

	Year Ended December 31,
	2017		2016		2015
United States	$	(5,974)	$	(11,843)	$	(9,232)
Foreign		387		215		788
Loss before provision for (benefit from) income taxes	$	(5,587)	$	(11,628)	$	(8,444)

Components of Provision for (Benefit from) Income Taxes

The provision for (benefit from) income taxes consisted of the following (in thousands):

	Year Ended December 31,
	2017		2016		2015
Current:
Federal	$	—	$	—	$	—
State		3		2		3
Foreign		98		(19)		(38)
Total current provision for (benefit from) income taxes		101		(17)		(35)
Deferred:
Federal		—		1		(26)
State		—		—		—
Total deferred provision for (benefit from) income taxes		—		1		(26)
Total	$	101	$	(16)	$	(61)

Reconciliation of Statutory Federal Income Tax to Effective Tax

The reconciliation of the federal statutory income tax to our effective tax is as follows (in thousands):

	Year Ended December 31,
	2017		2016		2015
Federal tax at statutory rate	$	(1,896)	$	(3,954)	$	(2,871)
State taxes		(877)		(184)		(155)
Foreign rate differential		(46)		(14)		(233)
Nondeductible expenses		453		(48)		161
Research and development credit		(174)		(180)		(153)
Stock compensation		218		784		109
Change in federal rate		12,231		—		—
Change in valuation allowance		(9,808)		3,580		3,081
Total	$	101	$	(16)	$	(61)

Schedule of Deferred Tax Assets and Liabilities

Significant components of our deferred tax assets and liabilities are as follows (in thousands):

	December 31,
	2017		2016
Deferred tax assets:
Net operating loss carryforwards	$	20,017	$	27,541
Accruals and reserves		2,234		4,502
Amortization of intangible assets		802		1,248
Tax credit carryforwards		3,443		2,808
Depreciation		(75)		602
Other		104		226
Gross deferred tax assets		26,525		36,927
Valuation allowance		(26,525)		(36,333)
Total deferred tax assets		—		594
Deferred tax liabilities:
Change in tax accounting method for reserves and		—		(594)
allowances
Amortization of intangible assets		(1)		(2)
Total deferred tax liabilities		(1)		(596)
Net deferred tax liability	$	(1)	$	(2)

Reconciliation of Unrecognized Tax Benefits

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

Balance as of December 31, 2014	$	2,984
Tax positions related to the current year:
Additions		436
Tax positions related to the prior year:
Reductions		(285)
Balance as of December 31, 2015		3,135
Tax positions related to the current year:
Additions		462
Tax positions related to the prior year:
Reductions		(7)
Balance as of December 31, 2016		3,590
Tax positions related to the current year:
Additions		665
Tax positions related to the prior year:
Reductions		(8)
Balance as of December 31, 2017	$	4,247