Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Components of Tax Provision (Benefit) Allocated to Continuing Operations

Components of tax provision (benefit) allocated to continuing operations include the following:

	Year Ended			Year Ended			Year Ended
	December 31,			December 31,			December 31,
	2017			2016			2015
Current:
Federal	$	8		$	—		$	(2	)
State		30			(11	)		49
Foreign		9			21			19
Sub-total	$	47		$	10		$	66
Deferred:
Federal	$	(253	)	$	—		$	—
State		—			—			—
Foreign		—			—			—
Sub-total	$	(253	)	$	—		$	—
Total tax provision (benefit)	$	(206	)	$	10		$	66

Reconciliation of Statutory Federal Income Tax Rate to Effective Income Tax Rate

The reconciliation of the statutory federal income tax rate to the Company’s effective income tax rate is as follows:

	Year Ended						Year Ended						Year Ended
	December 31,						December 31,						December 31,
	2017			%			2016			%			2015			%
Income taxes computed at statutory rates	$	(8,834	)		34	%	$	(7,369	)		34	%	$	(6,081	)		34	%
Increases (decreases) resulting from:
State income taxes, net of federal tax benefit		(1,576	)		6	%		(1,219	)		6	%		(1,298	)		7	%
Impact of federal graduated rates		—			—			—			—			(4	)		0	%
Federal and state research    and experimentation credits		(1,081	)		4	%		(1,112	)		5	%		(917	)		5	%
Change in valuation allowance		1,216			(5	)%		9,468			(44	)%		8,132			(45	)%
Impact of expired tax positions		7			0	%		(41	)		0	%		—			—
Impact of recent U.S. tax reform		10,529			(40	)%		—			—			—			—
Other		(467	)		2	%		283			(1	)%		234			(1	)%
Total	$	(206	)		1	%	$	10			0	%	$	66			0	%

Components of Deferred Tax Assets and Deferred Tax Liabilities

The tax effects of significant items comprising the Company’s deferred tax assets and deferred tax liabilities are as follows:

	Year Ended			Year Ended
	December 31,			December 31,
	2017			2016
Deferred tax assets:
Stock based compensation	$	926		$	1,524
Federal and state net operating losses		26,064			21,089
Goodwill		423			715
Accrued compensation		11			19
Deferred rent		281			344
Federal and state research and experimentation    credit		6,055			3,434
AMT credit		—			92
Intangible asset differences		222			253
Other		75			39
Total gross deferred tax assets		34,057			27,509
Less valuation allowance		(32,325	)		(24,888	)
Net deferred tax assets	$	1,732		$	2,621
Deferred tax liabilities:
Patent expenditures	$	(1,427	)	$	(2,012	)
Fixed asset differences		(305	)		(609	)
Total gross deferred tax liabilities	$	(1,732	)	$	(2,621	)
Total net deferred tax assets	$	—		$	—

Summary of Reconciliation of Uncertain Tax Positions

A summary reconciliation of the Company’s uncertain tax positions is as follows:

	Year Ended			Year Ended			Year Ended
	December 31,			December 31,			December 31,
	2017			2016			2015
Beginning balance	$	486		$	425		$	306
Addition for current year tax positions		101			100			74
Addition for prior year tax positions		16			2			45
Reduction for prior year positions		(52	)		—			—
Reduction for prior year positions resolved during the current year		(2	)		(41	)		—
Ending balance	$	549		$	486		$	425