Cash and Investments (Tables)

12 Months Ended

Dec. 30, 2017

Investments Debt And Equity Securities [Abstract]

Cash, Cash Equivalents and Available-for-Sale Investments

The following table presents cash, cash equivalents, and available-for-sale investments as of the following dates (in thousands):

	December 30, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Market Value
Cash	$	34,643	$	—	$	—		$	34,643
Cash equivalents:
Money market funds		256		—		—			256
Marketable securities:
U.S. Government agency securities		1,500		—		(5	)		1,495
Certificates of deposits		14,498		—		(1	)		14,497
Commercial paper		7,952		—		(3	)		7,949
Corporate debt securities		48,073		—		(105	)		47,968
Asset-backed securities		10,240		—		(19	)		10,221
Total cash, cash equivalents, and marketable    securities	$	117,162	$	—	$	(133	)	$	117,029
	December 31, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Market Value
Cash	$	43,604	$	—	$	—		$	43,604
Cash equivalents:
Money market funds		959		—		—			959
Commercial paper and corporate debt securities		2,499		—		—			2,499
Marketable securities:
U.S. Treasury securities		5,667		—		—			5,667
U.S. Government agency securities		11,412		—		(7	)		11,405
Certificates of deposits		23,000		19		—			23,019
Commercial paper		22,402		—		—			22,402
Corporate debt securities		14,194		—		(6	)		14,188
Municipal securities		756		—		(1	)		755
Asset-backed securities		5,466		—		(3	)		5,463
Total cash, cash equivalents, and marketable    securities	$	129,959	$	19	$	(17	)	$	129,961