Cash, Cash Equivalents and Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2018

Cash and Cash Equivalents [Abstract]

Amortized Cost and Fair Value of Cash, Cash Equivalents and Marketable Securities

The following table summarizes the amortized cost and fair value of the Company’s cash, cash equivalents and marketable securities as of December 31, 2018 (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Current assets:
Cash and cash equivalents:
Cash	$	5,222	$	—	$	—	$	5,222
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
Certificates of deposit	128,647		—		—		128,647
U.S. Treasuries	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

Cost and Fair Values of Marketable Securities

The following table summarizes the amortized cost and fair value of marketable securities based on stated effective maturities as of December 31, 2018 (in thousands):

	Amortized Cost		Fair Value
Due within one year	$	408,479	$	408,471
Due between one and two years	37,251		37,262
Total	$	445,730	$	445,733