Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Taxes at federal statutory rate	$ (9,563)	$ (18,123)
State taxes, net of federal benefit	(97)	(236)
Effect of tax rate differential for foreign subsidiary	176	(340)
Valuation allowance, including tax benefits of stock activity	5,609	(16,962)
Tax rate change	(244)	34,732
Discontinued operations	1,927	0
Stock-based compensation	513	224
Foreign withholding taxes	414	295
Return to provision adjustments	667	(2,931)
Subpart F income inclusion	0	2,998
SEC settlement penalty	0	959
Business combination	0	(1,914)
Other, net	(498)	1,857
Tax provision	$ (1,096)	$ 559

Effective Income Tax Rate Reconciliation, Acquisition of Business, Amount

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Effective Income Tax Rate Reconciliation, Penalty Settlement, Amount

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Income Tax Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Including Stock Activity

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Income Tax Reconciliation, Return to Provision Adjustments

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Income Tax Reconciliation, Subpart F Income Inclusion

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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