Note 2 - Marketable Securities (Tables)

12 Months Ended

Feb. 28, 2016

Notes Tables

Schedule of Fair Value of Separate Accounts by Major Category of Investment [Table Text Block]

	February 28, 2016
	Total		Level 1		Level 2		Level 3
U.S. Treasury and other government securities	$	118,194	$	118,194	$	-	$	-
U.S. corporate debt securities		21,474		21,474		-		-
Total marketable securities	$	139,668	$	139,668	$	-	$	-

	March 1, 2015
	Total		Level 1		Level 2		Level 3
U.S. Treasury and other government securities	$	119,493	$	119,493	$	-	$	-
U.S. corporate debt securities		11,102		7,084		4,018		-
Total marketable securities	$	130,595	$	126,577	$	4,018	$	-

Schedule of Unrealized Loss on Investments [Table Text Block]

	Amortized Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses
February 28, 2016:
U.S. Treasury and other government securities	$	117,897	$	372	$	74
U.S. corporate debt securities		21,554		-		81
Total marketable securities	$	139,451	$	372	$	155
March 1, 2015:
U.S. Treasury and other government securities	$	119,191	$	314	$	12
U.S. corporate debt securities		11,097		5		-
Total marketable securities	$	130,288	$	319	$	12

Realized Gain (Loss) on Investments [Table Text Block]

	Fiscal Year
	2016		2015		2014
Gross realized gains on sale	$	-	$	17	$	26
Gross realized losses on sale	$	-	$	44	$	209

Investments Classified by Contractual Maturity Date [Table Text Block]

Due in one year or less	$	51,166
Due after one year through five years		88,502
	$	139,668