Note 11 - Income Taxes (Details) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Apr. 30, 2015	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 30, 2011
Note 11 - Income Taxes (Details) [Line Items]
Undistributed Earnings of Foreign Subsidiaries			$ 214,300,000	$ 172,700,000
Deferred Tax Assets, Valuation Allowance			18,614,000	19,051,000
Unrecognized Tax Benefits			12,093,000	16,406,000	$ 14,922,000	$ 13,081,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate			2,700,000	4,800,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued			200,000	$ 500,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority							$ 10,500,000
Income Tax Examination, Penalties Accrued			0
Tax Adjustments, Settlements, and Unusual Provisions		$ 2,700,000
Income Tax Examination Tax Payment		1,600,000
Income Tax Examination, Interest Expense		$ 1,100,000
Increase In R & D Credits [Member]
Note 11 - Income Taxes (Details) [Line Items]
Federal R&D credit			1,900,000
Domestic Tax Authority [Member]
Note 11 - Income Taxes (Details) [Line Items]
Operating Loss Carryforwards			700,000
Tax Credit Carryforward, Amount			16,300,000
Domestic Tax Authority [Member] | Additional Paid-in Capital [Member]
Note 11 - Income Taxes (Details) [Line Items]
Operating Loss Carryforwards			700,000
Tax Credit Carryforward, Amount			7,400,000
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Note 11 - Income Taxes (Details) [Line Items]
Income Taxes Paid	$ 1,200,000		100,000
Interest Paid			1,000,000
State and Local Jurisdiction [Member]
Note 11 - Income Taxes (Details) [Line Items]
Operating Loss Carryforwards			22,800,000
Tax Credit Carryforward, Amount			15,600,000
State and Local Jurisdiction [Member] | Additional Paid-in Capital [Member]
Note 11 - Income Taxes (Details) [Line Items]
Operating Loss Carryforwards			22,800,000
Tax Credit Carryforward, Amount			$ 1,600,000