Note 8 - Acquired Intangible Assets, Net (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jan. 31, 2015
Amortization of Intangible Assets	$ 1,100	$ 1,100	$ 2,100
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	900
Finite-Lived Intangible Assets, Amortization Expense, Year Two	900
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	2,800
Finite-Lived Intangible Assets, Amortization Expense, Year Three	900
Finite-Lived Intangible Assets, Amortization Expense, Year Four	900
Finite-Lived Intangible Assets, Amortization Expense, Year Five	900
In Process Research Development [Member] | Research and Development Expense [Member]
Impairment of Intangible Assets, Finite-lived	$ 700	$ 700
Developed Technology Rights [Member] | Reclassified from in Process Research and Development [Member]
Finite-Lived Intangible Assets, Gross				$ 400