Income Taxes - Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income taxed at statutory rates	$ (2,125)	$ (4,212)
Stock-based compensation	79	46
Other adjustments	5	(87)
Prior year provision to actual adjustments	(2,867)	108
Change in US tax rate		2,487
Differences in tax rates	(339)	563
Effect of foreign exchange	(6)	(99)
Change in valuation allowance	$ 5,253	$ 1,194

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) in the income tax rates.

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