Note 8 - Income Taxes - Effective Tax Rate (Details)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	34.00%	34.00%	34.00%
State and local taxes	6.00%	6.00%	6.00%
Impact of Tax Act	4.00%
Non-U.S. income tax at different rates	(1.00%)
Domestic production activities deduction	(2.00%)	(1.00%)	(1.00%)
Other, net	(3.00%)	(2.00%)	(2.00%)
Effective rate	38.00%	37.00%	37.00%

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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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the income tax rates.

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