Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Schedule of reconciliation of income tax expense by applying federal income tax rate to loss before provision for income taxes

A reconciliation of income tax expense to the amount computed by applying the Federal income tax rate to loss before provision for income taxes as of December 31, 2017 and 2016 is as follows:

	2017			2016
Income tax credit at statutory rates	$	(268	)	$	(436	)
Nondeductible expenses		2			2
State income tax, net of federal benefits		(45	)		(66	)
Effect of US tax rate change		9,284			0
Expiration of stock options		188			149
Other		0			(5	)
Change in valuation allowance		(9,161	)		356
	$	—		$	—

Schedule of significant components of deferred income taxes

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred income taxes consist of the following:

	As of December 31,
	2017			2016
Deferred tax assets:
Net operating loss carryforwards	$	23,520		$	31,935
Inventory and other allowances		12			16
Charitable contribution carryforwards		2			5
Excess (tax) book depreciation		577			805
Excess (tax) book amortization		53			69
Share-based compensation		885			1,328
Other accrued costs		167			219
Total deferred tax assets		25,216			34,377
Less: Valuation allowance		(25,216	)		(34,377	)
Deferred income taxes	$	—		$	—