Cash and Investments (Tables)

9 Months Ended

Sep. 30, 2017

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):

	September 30, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Market Value
Cash	$	38,235	$	—	$	—		$	38,235
Cash equivalents:
Money market funds		812		—		—			812
Commercial paper and corporate debt securities		4,994		—		—			4,994
Marketable securities:
U.S. Treasury securities		501		—		—			501
U.S. Government agency securities		2,001		—		(5	)		1,996
Certificate of deposits		23,298		—		—			23,298
Commercial paper		17,907		3		—			17,910
Corporate debt securities		45,701		—		(4	)		45,697
Asset-backed securities		6,916		—		(2	)		6,914
Total cash, cash equivalents, and marketable securities	$	140,365	$	3	$	(11	)	$	140,357
	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