Note 5 - Financial Instruments Measured at Fair Value (Tables)

3 Months Ended

Mar. 30, 2019

Notes Tables

Available-for-sale Securities [Table Text Block]

	March 30, 2019
			Gross		Gross		Estimated
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses (1)		Value
Foreign government security	$	565	$	-	$	-	$	565

	December 29, 2018
			Gross		Gross		Estimated
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses (1)		Value
Foreign government security	$	560	$	-	$	-	$	560

Investments Classified by Contractual Maturity Date [Table Text Block]

	March 30, 2019				December 29, 2018
	Amortized		Estimated		Amortized		Estimated
	Cost		Fair Value		Cost		Fair Value
Due after one year through three years	$	565	$	565	$	560	$	560

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

	Fair value measurements at March 30, 2019 using:
							Total estimated
	Level 1		Level 2		Level 3		fair value
Cash	$	139,640	$	-	$	-	$	139,640
Money market funds		-		19,881		-		19,881
Foreign government security		-		565		-		565
	$	139,640	$	20,446	$	-	$	160,086

	Fair value measurements at December 29, 2018 using:
							Total estimated
	Level 1		Level 2		Level 3		fair value
Cash	$	144,696	$	-	$	-	$	144,696
Money market funds		-		19,764		-		19,764
Foreign government security		-		560		-		560
	$	144,696	$	20,324	$	-	$	165,020