Cash and Investments (Tables)

6 Months Ended

Jun. 30, 2018

Investments Debt And Equity Securities [Abstract]

Cash, Cash Equivalents and Available-for-Sale Investments

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

	June 30, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Market Value
Cash	$	70,657	$	—	$	—		$	70,657
Cash equivalents:
Money market funds		9,563		—		—			9,563
Commerical paper and Certificates of deposit		5,980		—		—			5,980
Marketable securities:
U.S. Government agency securities		1,500		—		(1	)		1,499
Certificates of deposit		8,999		1		—			9,000
Commercial paper		4,974		—		—			4,974
Corporate debt securities		36,807		—		(130	)		36,677
Asset-backed securities		10,383		—		(31	)		10,352
Total cash, cash equivalents, and marketable securities	$	148,863	$	1	$	(162	)	$	148,702
	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