Note 7 - Income Taxes (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Period of Foreign Tax Credits Carried Forward	10 years
Foreign Tax Credit Carry forwards Expiring Within One Year	$ 33.5
Tax Credit Carryforward, Valuation Allowance	21.8
Increase (Decrease) in Deferred Income Taxes	$ 2.9
Minimum Percentage of Probability for Determination of Income Tax Effects	50.00%	50.00%
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 9.3
Foreign Earnings Repatriated	40.0	$ 200.0
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount	14.0
Undistributed Earnings of Foreign Subsidiaries	$ 565.3
Incremental US Tax if Earnings were Repatriated, Percent	35.00%
Foregin Cash and Cash Equivalents, Balance Suject to Domestic Tax Upon Repatriation	$ 8.6
Liability for Uncertainty in Income Taxes, Noncurrent	21.1	$ 24.7	$ 24.7
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	11.9
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	1.0
Uncertain Tax Positions [Member]
Increase (Decrease) in Deferred Income Taxes	(3.3)
Domestic Tax Authority [Member]
Operating Loss Carryforwards	$ 153.2
Domestic Tax Authority [Member] | Earliest Tax Year [Member]
Open Tax Year	2002
Foreign Tax Authority [Member]
Tax Credit Carryforward, Valuation Allowance	$ 21.8
Foreign Tax Authority [Member] | Latest Tax Year [Member]
Open Tax Year	2014
Foreign Tax Authority [Member] | MEXICO
Operating Loss Carryforwards	$ 4.4
Foreign Tax Authority [Member] | UNITED KINGDOM
Operating Loss Carryforwards	0.4
Foreign Tax Authority [Member] | BRAZIL
Operating Loss Carryforwards	22.6
Foreign Tax Authority [Member] | NORWAY
Operating Loss Carryforwards	$ 6.8