Note 3 - Marketable Securities - Summary of Unrealized Gains/Losses on Available-for-Sale Securities (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Aug. 30, 2015	Mar. 01, 2015
US Treasury and Government [Member]
Amortized Cost Basis	$ 108,055	$ 119,191
Gross Unrealized Gains	356	314
Gross Unrealized Losses	27	12
Domestic Corporate Debt Securities [Member]
Amortized Cost Basis	31,790	11,097
Gross Unrealized Gains	0	5
Gross Unrealized Losses	90	0
Amortized Cost Basis	139,845	130,288
Gross Unrealized Gains	356	319
Gross Unrealized Losses	$ 117	$ 12