Note 3 - Marketable Securities - Summary of Available-for-Sale Securities (Details) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2014	Mar. 02, 2014
Marketable securities (Note 3)	$ 135,051	$ 137,206	[1]
Fair Value, Inputs, Level 1 [Member]
Marketable securities (Note 3)	121,032	130,122
Fair Value, Inputs, Level 2 [Member]
Marketable securities (Note 3)	14,019	7,084
Domestic Corporate Debt Securities [Member]
Marketable securities (Note 3)	20,309	24,413
Domestic Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable securities (Note 3)	6,290	17,329
Domestic Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Marketable securities (Note 3)	14,019	7,084
US Treasury and Government [Member]
Marketable securities (Note 3)	114,742	112,793
US Treasury and Government [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable securities (Note 3)	$ 114,742	$ 112,793

[1] The balance sheet at March 2, 2014 has been derived from the audited financial statements at that date.