Note 3 - Marketable Securities (Tables)

9 Months Ended

Nov. 26, 2017

Notes Tables

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

	November 26, 2017
	Total		Level 1		Level 2		Level 3
U.S. Treasury and other government securities	$	158,276	$	158,276	$	-	$	-
U.S. corporate debt securities		42,957		42,957		-		-
Total marketable securities	$	201,233	$	201,233	$	-	$	-

	February 26, 2017
	Total		Level 1		Level 2		Level 3
U.S. Treasury and other government securities	$	111,261	$	111,261	$	-	$	-
U.S. corporate debt securities		24,891		24,891		-		-
Total marketable securities	$	136,152	$	136,152	$	-	$	-

Schedule of Unrealized Loss on Investments [Table Text Block]

	Amortized Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses
November 26, 2017:
U.S. Treasury and other government securities	$	159,928	$	-	$	1,652
U.S. corporate debt securities		43,275		-		318
Total marketable securities	$	203,203	$	-	$	1,970
February 26, 2017:
U.S. Treasury and other government securities	$	111,727	$	136	$	602
U.S. corporate debt securities		24,938		1		48
Total marketable securities	$	136,665	$	137	$	650

Investments Classified by Contractual Maturity Date [Table Text Block]

Due in one year or less	$	23,607
Due after one year through five years		177,626
	$	201,233