Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Components of Tax Benefit (Provision) Allocated to Continuing Operations

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

	Year Ended			Year Ended
	December 31,			December 31,
	2018			2017
Current:
Federal	$	—		$	(8	)
State		(28	)		(30	)
Foreign		(11	)		(9	)
Sub-total	$	(39	)	$	(47	)
Deferred:
Federal	$	—		$	253
State		—			—
Foreign		—			—
Sub-total	$	—		$	253
Total tax benefit (provision)	$	(39	)	$	206

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
	December 31,						December 31,
	2018			%			2017			%
Income taxes computed at statutory rates	$	6,818			(21	)%	$	8,834			(34	)%
(Increases) decreases resulting from:
State income taxes, net of federal tax benefit		2,054			(6	)%		1,576			(6	)%
Federal and state research and experimentation credits		1,064			(4	)%		1,081			(4	)%
Change in valuation allowance		(10,024	)		31	%		(1,216	)		5	%
Impact of expired tax positions		1			—	%		(7	)		—	%
Impact of recent U.S. tax reform		—			—	%		(10,529	)		40	%
Other		48			—	%		467			(2	)%
Total	$	(39	)		—	%	$	206			(1	)%

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,
	2018			2017
Deferred tax assets:
Stock based compensation	$	998		$	926
Federal and state net operating losses		34,873			26,064
Goodwill		341			423
Accrued compensation		11			11
Deferred rent		290			281
Federal and state research and experimentation credit		7,528			6,055
Intangible asset differences		185			222
Other		76			75
Total gross deferred tax assets		44,302			34,057
Less valuation allowance		(42,349	)		(32,325	)
Net deferred tax assets	$	1,953		$	1,732
Deferred tax liabilities:
Patent expenditures	$	(1,442	)	$	(1,427	)
Fixed asset differences		(511	)		(305	)
Total gross deferred tax liabilities	$	(1,953	)	$	(1,732	)
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
	December 31,			December 31,
	2018			2017
Beginning balance	$	549		$	486
Addition for current year tax positions		88			101
Addition for prior year tax positions		—			16
Reduction for prior year positions		(23	)		(52	)
Reduction for prior year positions resolved during the current year		(1	)		(2	)
Ending balance	$	613		$	549