Note 10 - Employee Equity Incentive Plans - Allocated Share-based Compensation Expense (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Cost of Sales [Member]
Stock-based Compensation Effect in Income before Taxes		$ 124	$ 102	$ 246	$ 210
Research and Development Expense [Member]
Stock-based Compensation Effect in Income before Taxes	[1]	330	189	791	378
Selling, General and Administrative Expenses [Member]
Stock-based Compensation Effect in Income before Taxes		497	406	903	790
Stock-based Compensation Effect in Income before Taxes		951	697	1,940	1,378
Provision for income taxes	[2]	333	244	679	482
Net stock-based compensation effects in net income		$ 618	$ 453	$ 1,261	$ 896

[1] Includes acquisition-related compensation expenses of $249,000 during the six months ended September 30, 2015.

[2] Calculated at the U.S. statutory federal income tax rate of 35% in fiscal 2016 and 2015.