Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of Components of Loss Before Provision for Income Taxes

The components of the Company’s loss before provision for income taxes were as follows:

	Years Ended December 31,
	2017			2016			2015
United States of America	$	(15,740	)	$	(7,595	)	$	(17,173	)
International		(14,744	)		(7,481	)		(15,171	)
	$	(30,484	)	$	(15,076	)	$	(32,344	)

Schedule of Components of Provision for Income Taxes

The components of the provision for income taxes were as follows:

	Years Ended December 31,
	2017			2016			2015
Current income tax provision
Federal	$	—		$	—		$	—
State		64			58			111
Foreign		1,301			1,708			1,193
Total current income tax provision		1,365			1,766			1,304
Deferred income tax benefit
Federal		—			—			-
State		—			—			-
Foreign		(358	)		(362	)		(299	)
Total deferred income tax benefit		(358	)		(362	)		(299	)
Provision for income taxes	$	1,007		$	1,404		$	1,005

Differences in Total Provision for Income Taxes

The differences in the total provision for income taxes that would result from applying the 34% federal statutory rate to loss before provision for income taxes and the reported provision for income taxes were as follows:

	Years Ended December 31,
	2017			2016			2015
Tax benefit at U.S. statutory rate	$	(10,365	)	$	(5,126	)	$	(10,997	)
State income taxes, net of federal benefit		(2,858	)		(147	)		(104	)
Foreign income and withholding taxes		5,578			4,317			6,033
Impact of change to U.S. statutory rate from Tax Cuts and Jobs Act		14,302			—			—
Stock-based compensation		1,085			2,231			1,039
Change in valuation allowance		(8,158	)		155			3,807
Research and development credits		(382	)		(736	)		(1,067	)
Uncertain tax positions		1,995			1,146			1,277
Provision to return adjustments		153			(484	)		848
Impact of adoption of ASU 2016-09		(1,291	)		—			—
Other		948			48			169
	$	1,007		$	1,404		$	1,005

Schedule of Components of Company's Deferred Tax Assets (Liabilities)

Major components of the Company’s deferred tax assets (liabilities) as of December 31, 2017 and 2016 are as follows:

	December 31,
	2017			2016
Net operating loss	$	25,002		$	32,551
Accruals and reserves		1,656			2,934
Research and development credits		8,757			7,368
Stock-based compensation		2,796			4,622
Property and equipment and intangible assets		(710	)		(1,855	)
Other		3,161			2,842
Net deferred tax assets		40,662			48,462
Valuation allowance		(41,224	)		(49,382	)
Total non-current net deferred tax liabilities, net of valuation allowance	$	(562	)	$	(920	)

Change in Uncertain Tax Positions

The aggregate changes in the balance of gross uncertain tax positions were as follows:

Ending balance as of December 31, 2014	$	1,581
Increase in balances related to tax positions taken during the current period		3,196
Increase in balances related to tax positions taken during the prior period		2,781
Ending balance as of December 31, 2015		7,558
Decrease in balances related to tax positions taken during the current period		(2	)
Increase in balances related to tax positions taken during the prior period		1,240
Ending balance as of December 31, 2016		8,796
Increase in balances related to tax positions taken during the current period		1,738
Decrease in balances related to tax positions taken during the prior period		(9	)
Decrease in balances due to change in United States statutory rate		(2,101	)
Ending balance as of December 31, 2017	$	8,424