Note 6 - Income Taxes (Details Textual) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	$ 3.9
Foreign Earnings Repatriated		$ 240.0
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount		84.0
Undistributed Earnings of Foreign Subsidiaries	553.0	$ 553.0
Incremental US Tax if Earnings were Repatriated, Percent		35.00%
Foregin Cash and Cash Equivalents, Balance Suject to Domestic Tax Upon Repatriation	$ 8.6	$ 8.6