Note 2 - Marketable Securities - Summary of Unrealized Gains/Losses on Available-for-Sale Securities (Details) - USD ($)	12 Months Ended
	Feb. 28, 2016	Mar. 01, 2015
US Treasury and Government [Member]
Amortized Cost Basis	$ 117,897,000	$ 119,191,000
Gross Unrealized Gains	372,000	314,000
Gross Unrealized Losses	74,000	12,000
Domestic Corporate Debt Securities [Member]
Amortized Cost Basis	21,554,000	11,097,000
Gross Unrealized Gains	0	$ 5,000
Gross Unrealized Losses	81,000
Amortized Cost Basis	139,451,000	$ 130,288,000
Gross Unrealized Gains	372,000	319,000
Gross Unrealized Losses	$ 155,000	$ 12,000