Cash, Cash Equivalents and Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2019

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 our cash, cash equivalents and marketable securities by major investment category as of December 31, 2019 and 2018 (in thousands):

	December 31, 2019
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Current assets:
Cash and cash equivalents:
Cash	$	43,058	$	—	$	—	$	43,058
Money market funds	11,527		—		—		11,527
Commercial paper	7,485		—		—		7,485
Total cash and cash equivalents	$	62,070	$	—	$	—	$	62,070
Marketable securities:
Commercial paper	$	73,366	$	—	$	—	$	73,366
Corporate debt securities	74,038		381		(2)		74,417
Certificates of deposit	41,302		—		—		41,302
Total marketable securities	$	188,706	$	381	$	(2)	$	189,085
Total cash, cash equivalents and marketable securities	$	250,776	$	381	$	(2)	$	251,155

	December 31, 2018
	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, 2019 (in thousands):

	Amortized Cost		Estimated Fair Value
Due within one year	$	156,620	$	156,833
Due between one and two years	32,086		32,252
Total	$	188,706	$	189,085