Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Taxes [Abstract]
U.S. federal corporate tax rate			21.00%		35.00%
Income tax provision	$ 106	$ (211)	$ 41	$ (529)
Deferred income taxes (Note 7)	779		779		$ 741
Unrecognized tax benefits	700		700		677
Interest and penalties	$ 289		$ 289		$ 266

Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences, with jurisdictional netting and classified as noncurrent.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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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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Amount of unrecognized tax benefits.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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