Note 12 - Stock-based Compensation (Details) - Stock-based Compensation Expense Related to Stock Options and RSUs - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based Compensation Expense	$ 1,452	$ 3,600	$ 3,389	$ 6,727
Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based Compensation Expense	85	227	172	487
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based Compensation Expense	205	870	654	1,682
Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based Compensation Expense	$ 1,162	$ 2,503	$ 2,563	$ 4,558