Note 13 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	35.00%	35.00%
Deferred Tax Assets, Net, Noncurrent	$ 163	$ 3,238
Deferred Tax Liabilities, Net, Noncurrent	71,300	41,852
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	(1,015)	2,454	$ 638
Tax Credit Carry Forward State Research and Development	10,349
Tax Credit Carryforward State Manufacturing	9,254
Unrecognized Tax Benefits, Interest on Income Taxes Expense	37	131	272
Unrecognized Tax Benefits, Income Tax Penalties Expense	$ 136	$ 220	$ 425
State and Local Jurisdiction [Member]
Open Tax Year	2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
Foreign Tax Authority [Member]
Open Tax Year	2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017