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Note H - Income Taxes (Details Textual) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2018
Effective Income Tax Rate Reconciliation, Percent	153.10%	29.60%	97.31%	30.10%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	28.06%		28.06%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Transition Tax Liability	$ 1,815,966		$ 1,815,966
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount	775,000		775,000
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability	664,000		664,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 0		$ 0
Earliest Tax Year [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Open Tax Year			2014
Earliest Tax Year [Member] | Foreign Tax Authority [Member] | Swiss Federal Tax Administration (FTA) [Member]
Open Tax Year			2015
Earliest Tax Year [Member] | State and Local Jurisdiction [Member]
Open Tax Year			2007
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent					28.06%

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- Definition

The amount of income tax expense (benefit) adjusted due to the transition into new legislation.

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

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

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Amount of income tax expense (benefit) from continuing operations attributable to an adjustment of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity.

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Tax year that remains open to examination under enacted tax laws, in CCYY format.

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