Investments (Tables)

6 Months Ended

Jun. 30, 2019

Investments, Debt and Equity Securities [Abstract]

Summary of Marketable Securities

The following is a summary of investments in marketable securities, including those that meet the definition of a cash equivalent, as of June 30, 2019 (in thousands):

	June 30, 2019
	Amortized Cost Basis		Unrealized Gains		Unrealized Losses		Fair Value		Cash Equivalent		Investments
Money market funds	$	267,372	$	—	$	—	$	267,372	$	267,372	$	—
Corporate bonds	7,996		2		—		7,998		—		7,998
U.S. treasury securities	19,991		2		—		19,993		19,993		—
Commercial paper	25,492		—		—		25,492		25,492		—
Total	$	320,851	$	4	$	—	$	320,855	$	312,857	$	7,998

The following is a summary of investments in marketable securities, including those that meet the definition of a cash equivalent, as of December 31, 2018 (in thousands):

	December 31, 2018
	Amortized Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value		Cash Equivalent		Investments
Money market funds	$	129,321	$	—	$	—		$	129,321	$	129,321	$	—
Corporate bonds	58,115		—		(82		)	58,033		—		58,033
U.S. treasury securities	138,826		—		(100		)	138,726		—		138,726
Commercial paper	7,973		—		—			7,973		—		7,973
Total	$	334,235	$	—	$	(182	)	$	334,053	$	129,321	$	204,732