Note 7 - Income Taxes (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	26.00%	25.00%	25.30%	24.70%
Unrecognized Tax Benefits	$ 94.5		$ 94.5
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	79.1		79.1
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 10.0		$ 10.0