Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Summary of Income Tax Current and Deferred Provision (Benefit)

The following table presents the current and deferred provision (benefit) for income taxes for the years ended December 31 (in thousands):

	2015		2014		2013
Current:
Federal	$	—	$	—	$	(138	)
State		30		27		31
Foreign		87		25		(27	)
		117		52		(134	)
Deferred:
Federal		61		60		72
State		—		—		(118	)
Foreign		—		—		16
		61		60		(30	)
	$	178	$	112	$	(164	)

Federal Income Tax Provision Compared With Statutory Rates

The provision for income taxes differs from the amount that would result from applying the federal statutory rate as follows for the years ended December 31:

	2015				2014				2013
Statutory regular federal income tax rate		(34.0	)	%		(34.0	)	%		(34.0	)	%
Change in valuation allowance		40.2		%		37.4		%		27.0		%
Tax return to prior year provision adjustments		—		%		—		%		(0.9	)	%
Reduction of net operating loss attributes		—		%		—		%		(3.1	)	%
State tax benefit (net of federal benefit)		(3.1	)	%		(3.3	)	%		(4.2	)	%
Research credits		(3.1	)	%		(1.9	)	%		(2.1	)	%
Foreign amounts with no tax benefit		0.1		%		(0.1	)	%		(0.2	)	%
Non-deductible expenses		0.4		%		1.0		%		1.6		%
Effect of change in rate		0.9		%		2.3		%		14.2		%
Other		(0.5	)	%		(0.8	)	%		0.3		%
Total		0.9		%		0.6		%		(1.4	)	%

Summary of Net Deferred Tax Assets and Net Deferred Tax Liabilities

The components of the deferred income tax assets and liabilities as of December 31 (in thousands):

	2015			2014
Capitalized intangible assets for tax purposes	$	104		$	202
Reserves not currently deductible		2,527			1,871
Deferred revenue		8			8
Stock options		4,072			2,911
State taxes		9			8
Income tax credits		2,471			2,200
Inventory		905			1,225
Property and equipment		345			280
Other comprehensive income		320			222
Unrealized gain on foreign currency		136			136
Net operating losses		38,753			33,140
Total deferred tax assets		49,650			42,203
Valuation allowance		(49,514	)		(42,069	)
Net deferred tax assets		136			134
Capitalized intangible assets		(813	)		(752	)
Other		(61	)		(59	)
Total deferred tax liabilities		(874	)		(811	)
Net deferred tax liabilities	$	(738	)	$	(677	)

Summary of Unrecognized Tax Benefits

The following table summarizes the activity related to the Company’s unrecognized tax benefits during the year ended December 31, 2015 (in thousands):

Balance at January 1, 2015	$	568
Additions for tax positions related to the prior year		—
Lapse of statute of limitations		—
Balance at December 31, 2015	$	568