Note 4 - Financial Instruments Measured at Fair Value (Tables)

6 Months Ended

Jun. 25, 2016

Notes Tables

Available-for-sale Securities [Table Text Block]

	June 25, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Corporate debt securities	$	7,647	$	-	$	-	$	7,647
Foreign government security		655		-		-		655
Bank certificates of deposit		913		-		-		913
	$	9,215	$	-	$	-	$	9,215

	December 26, 2015
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Foreign government security	$	650	$	-	$	-	$	650
Bank certificates of deposit		1,002		-		-		1,002
	$	1,652	$	-	$	-	$	1,652

Investments Classified by Contractual Maturity Date [Table Text Block]

	June 25, 2016				December 26, 2015
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due in one year or less	$	9,215	$	9,215	$	1,450	$	1,450
Due after one year through three years		-		-		202		202
	$	9,215	$	9,215	$	1,652	$	1,652

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	Fair value measurements at June 25, 2016 using:
							Total estimated
	Level 1		Level 2		Level 3		fair value
Cash	$	65,878	$	-	$	-	$	65,878
Corporate debt securities		-		15,045		-		15,795
Money market funds		-		35,437		-		35,437
Bank certificates of deposit		-		913		-		163
Foreign government security		-		655		-		655
	$	65,878	$	52,050	$	-	$	117,928

	Fair value measurements at December 26, 2015 using:
							Total estimated
	Level 1		Level 2		Level 3		fair value
Cash	$	73,746	$	-	$	-	$	73,746
Foreign government security		-		650		-		650
Money market funds		-		41,624		-		41,624
Bank certificates of deposit		-		1,002		-		1,002
	$	73,746	$	43,276	$	-	$	117,022