Marketable Securities (Tables)

6 Months Ended

Jul. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Summary of Marketable Securities

As of July 31, 2020 and January 31, 2020, our marketable securities consisted of the following: 

	As of July 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(in thousands)
Commercial paper	$	6,990	$	—	$	—	$	6,990
Agency bonds	302,221		193		(45)		302,369
Corporate and other debt securities	362,539		2,571		(28)		365,082
U.S. government agency securities	43,479		81		—		43,560
Treasury bills	14,994		—		—		14,994
Marketable securities	$	730,223	$	2,845	$	(73)	$	732,995

	As of January 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(in thousands)
Commercial paper	$	37,894	$	—	$	—	$	37,894
Agency bonds	141,157		49		(43)		141,163
Corporate and other debt securities	320,407		775		(16)		321,166
U.S. government agency securities	71,794		45		(2)		71,837
Marketable securities	$	571,252	$	869	$	(61)	$	572,060

Summary of Contractual Maturities of Marketable Securities

The following table presents the contractual maturities of our marketable securities as of July 31, 2020 and January 31, 2020:

	As of
	July 31, 2020		January 31, 2020
	(in thousands)
Less than one year	$	400,094	$	315,900
Due in one to five years	332,901		256,160
Total	$	732,995	$	572,060