Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Components Of Income Tax Expense Benefit [Line Items]
Computed "expected" tax-benefit - Federal	$ (2,818)	$ (5,267)
Computed "expected" tax-benefit - State	(636)	(613)
Adjustment of "expected" tax-benefit to actual	19	(2)
Meals, entertainment and other	3	10
Non-deductible stock-based compensation	266	502
Fair Market Value Adjustment - Warrants	(1,051)	(4,076)
Impact of U.S. tax reform	0	21,555
Change in valuation allowance	4,217	(12,109)
Income tax expense	$ 0	$ 0

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