Note 5 - Income Taxes (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Percent	20.40%	42.00%
Unrecognized Tax Benefits			$ 7.4
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 0.7		$ 0.6
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0.1	$ 0.2
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 1.0