Income Taxes (Details) - USD ($)	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Taxes [Abstract]
U.S. federal corporate tax rate			21.00%		35.00%
Income tax provision	$ 6,000	$ 139,000	$ 65,000	$ 318,000
Deferred income taxes (Note 7)	766,000		766,000		$ 741,000
Unrecognized tax benefits	692,000		692,000		677,000
Interest and penalties	$ 281,000		$ 281,000		$ 266,000

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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