Cash, Cash Equivalents and Marketable Securities

6 Months Ended

Jun. 30, 2019

Cash and Cash Equivalents [Abstract]

Cash, Cash Equivalents, and Marketable Securities

Cash, Cash Equivalents and Marketable Securities

The following tables summarize the amortized cost and the estimated fair value of our cash, cash equivalents and marketable securities as of June 30, 2019 and December 31, 2018 (in thousands):

	June 30, 2019
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Current assets:
Cash	$	18,157	$	—	$	—	$	18,157
Cash equivalents:
Commercial paper	17,443		—		—		17,443
Money market funds	15,188		—		—		15,188
Total cash equivalents	32,631		—		—		32,631
Total cash and cash equivalents	50,788		—		—		50,788
Marketable securities:
Commercial paper	153,691		—		—		153,691
Corporate debt securities	83,108		431		(5)		83,534
Certificate of deposits	70,175		—		—		70,175
U.S. Treasuries	104,480		300		—		104,780
Total marketable securities	411,454		731		(5)		412,180
Total cash, cash equivalents and marketable securities	$	462,242	$	731	$	(5)	$	462,968

	December 31, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Current assets:
Cash	$	5,222	$	—	$	—	$	5,222
Cash equivalents:
Money market funds	63,232		—		—		63,232
Total cash and cash equivalents	68,454		—		—		68,454
Marketable securities:
Commercial paper	152,940		—		—		152,940
Corporate debt securities	60,622		58		(75)		60,605
Certificate of deposits	128,647		—		—		128,647
U.S. Treasury securities	103,521		31		(11)		103,541
Total marketable securities	445,730		89		(86)		445,733
Total cash, cash equivalents and marketable securities	$	514,184	$	89	$	(86)	$	514,187

The following table summarizes the cost and fair value of marketable securities based on stated effective maturities as of June 30, 2019 (in thousands):

	Amortized Cost		Fair Value
Due within one year	$	361,446	$	361,814
Due between one and two years	50,008		50,366
Total	$	411,454	$	412,180

There have been no significant realized gains or losses on available-for-sale securities for the periods presented. As of June 30, 2019, available-for-sale debt securities that were in a continuous loss position but were not deemed to be other than temporarily impaired were not material.

See Note 5 for further information regarding the fair value of our financial instruments.