Income Taxes (Details Textual) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) affiliate	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Income Tax Examination [Line Items]
Income tax expense	$ 23	$ 23	$ 47	$ 106
Effective income tax rate reconciliation, percent	0.20%	2.60%	0.30%	589.00%
Number of foreign affiliates subject to tax in Estonia | affiliate			1
Tax rate for earnings and profits as they are generated			0.00%
Remeasurement at new rate, percent			21.00%
Operating loss carryforwards					$ 41,700
Change in ownership percent					50.00%
Ownership change (greater than)					5.00%
Minimum
Income Tax Examination [Line Items]
Tax rate for earnings and profits that are distributed to shareholders			14.00%
Tax rate applied to dividends			14.00%
Maximum
Income Tax Examination [Line Items]
Tax rate for earnings and profits that are distributed to shareholders			20.00%
Tax rate applied to dividends			20.00%
Not Subject to Limitations | Subsequent To Change Date In 2010
Income Tax Examination [Line Items]
Operating loss carryforwards					$ 23,100
Subject to Limitations | Minimum
Income Tax Examination [Line Items]
Operating loss carryforwards					1,000
Subject to Limitations | Maximum
Income Tax Examination [Line Items]
Operating loss carryforwards					$ 2,300
Alternative Minimum Tax Carryover
Income Tax Examination [Line Items]
Credit receivable	$ 100		$ 100