Note 8 - Income Taxes (Details Textual) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	25.10%	26.00%	24.00%	26.00%
Unrecognized Tax Benefits, Ending Balance	$ 50.2		$ 50.2
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	41.5		41.5
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	$ 6.1		$ 6.1

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

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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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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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