Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Reconciliation of Total Income Tax Provision

A reconciliation of the total income tax provision tax rate to the statutory federal income tax rate of 34% for the years ended December 31, 2016 and 2015 is as follows:

	2016			2015
Income tax expense (benefit) at federal statutory rate		(34.00	)%		(34.00	)%
Income tax expense (benefit) at state statutory rate		(3.41	)%		(4.40	)%
Mark to market permanent adjustment		0.00	%		(13.91	)%
Change in valuation allowance		16.75	%		(7.45	)%
Change in state rate		(0.06	)%		(0.09	)%
Permanent interest adjustments		0.16	%		6.25	%
Stock compensation		12.67	%		20.43	%
Transfer pricing		0.00	%		18.49	%
Research credit		(1.44	)%		(2.37	)%
Foreign rate differential		0.79	%		0.69	%
NOLs expiring and adjustments to NOL		6.00	%		13.92	%
Other, net		2.54	%		2.44	%
		0.00	%		0.00	%

Deferred Tax Assets and Liabilities

The tax effects of temporary differences that give rise to significant portions of our deferred tax assets and deferred tax liabilities as of December 31, 2016 and 2015 are as follows (in thousands):

	2016			2015
Deferred tax assets:
Allowances and reserves	$	573		$	673
Accrued expenses		701			951
Deferred revenue and gain-on-sale		33			39
Stock based compensation		1,947			4,547
Net operating loss carryforwards		125,182			119,000
Income tax credit carryforwards		7,764			7,437
Property and equipment, principally due to differences in depreciation		675			683
Other, net		15			16
		136,890			133,346
Valuation allowance		(134,873	)		(131,187	)
Total deferred tax assets, net of allowance		2,017			2,159
Deferred tax liabilities:
Intangibles assets		(2,017	)		(2,159	)
Total deferred tax liability		(2,017	)		(2,159	)
Net deferred tax assets (liability)	$	—		$	—

Unrecognized Tax Benefits Activity

Following is a tabular reconciliation of the unrecognized tax benefits activity during the years ended December 31, 2016 and 2015 (in thousands):

	2016			2015
Unrecognized Tax Benefits – Beginning	$	1,987		$	1,852
Gross increases – tax positions in prior period		1			—
Gross decreases – tax positions in prior period		(13	)		—
Gross increase – current-period tax positions		87			135
Unrecognized Tax Benefits – Ending	$	2,062		$	1,987