Note 6 - Fair Value (Details) - Cash, Cash Equivalents and Short-Term Marketable Securities (USD $) In Thousands, unless otherwise specified	Mar. 30, 2014	Mar. 31, 2013	Apr. 01, 2012	Mar. 27, 2011
Cash and cash equivalents
Cash in financial institutions	$ 9,978	$ 9,676
Money market funds	4,636	5,042
Total cash and cash equivalents	14,614	14,718	8,714	15,039
Short-term marketable securities
Short-term marketable securities	152,420	190,587
US Government Agencies Debt Securities [Member]
Short-term marketable securities
Short-term marketable securities	22,512	41,721
US States and Political Subdivisions Debt Securities [Member]
Short-term marketable securities
Short-term marketable securities	2,772	2,935
Corporate Debt Securities [Member]
Short-term marketable securities
Short-term marketable securities	71,253	92,229
Asset-backed Securities [Member]
Short-term marketable securities
Short-term marketable securities	27,635	30,966
Collateralized Mortgage Backed Securities [Member]
Short-term marketable securities
Short-term marketable securities	$ 28,248	$ 22,736