Note 7 - Income Taxes (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%
Income Taxes Receivable	$ 76.7	$ 79.8
Unrecognized Tax Benefits	32.0	31.6	$ 29.7	$ 25.8
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	20.8	20.5
Income Tax Examination, Penalties and Interest Accrued	1.9	1.8	$ 1.9
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 4.0	$ 3.5