Note 2 - Marketable Securities (Tables)

12 Months Ended

Feb. 25, 2018

Notes Tables

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

	February 25, 2018
	Total		Level 1		Level 2		Level 3
U.S. Treasury and other government securities	$	78,361	$	78,361	$	-	$	-
U.S. corporate debt securities		11,616		11,616		-		-
Total marketable securities	$	89,977	$	89,977	$	-	$	-

	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
February 25, 2018:
U.S. Treasury and other government securities	$	80,116	$	-	$	1,755
U.S. corporate debt securities		11,675		-		59
Total marketable securities	$	91,791	$	-	$	1,814
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

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

	Fiscal Year
	2018		2017		2016
Gross realized gains on sale	$	-	$	-	$	-
Gross realized losses on sale	$	1,342	$	-	$	-

Investments Classified by Contractual Maturity Date [Table Text Block]

Due in one year or less	$	15,429
Due after one year through five years		74,548
	$	89,977