Investments (Tables)

12 Months Ended

Dec. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Schedule of Available-for-sale Securities by Security Type

Cash equivalents, short-term investments and long-term investments as of December 31, 2018 were comprised as follows (in thousands):

	December 31, 2018
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents and short-term investments:
Money market funds, included in cash equivalents	$	41,434	$	—	$	—		$	41,434
Corporate debt securities	65,887		2		(39		)	65,850
U.S. Treasuries	53,765		1		(8		)	53,758
Government agency securities	28,866		—		(34		)	28,832
Total cash equivalents and short-term investments	189,952		3		(81		)	189,874
Long-term investments:
Corporate debt securities	2,001		—		(8		)	1,993
Government agency securities	3,989		8		—			3,997
Total long-term investments	5,990		8		(8		)	5,990
Total cash equivalents and investments	$	195,942	$	11	$	(89	)	$	195,864

Cash equivalents, short-term investments and long-term investments as of December 31, 2017 were comprised as follows (in thousands):

	December 31, 2017
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents and short-term investments:
Money market funds, included in cash equivalents	$	21,059	$	—	$	—		$	21,059
Corporate debt securities	58,136		—		(64		)	58,072
U.S. Treasuries	111,049		—		(101		)	110,948
Government agency securities	43,204		—		(131		)	43,073
Total cash equivalents and short-term investments	233,448		—		(296		)	233,152
Long-term investments:
Corporate debt securities	7,117		—		(16		)	7,101
Government agency securities	15,195		—		(97		)	15,098
Total long-term investments	22,312		—		(113		)	22,199
Total cash equivalents and investments	$	255,760	$	—	$	(409	)	$	255,351