Fair Value Measurements (Tables)

12 Months Ended

Jan. 31, 2021

Fair Value Disclosures [Abstract]

Schedule of Financial Instruments Measured at Fair Value on Recurring Basis

The following tables present information about our financial instruments that are measured at fair value on a recurring basis and indicate the fair value hierarchy of the valuation inputs utilized to determine such fair value:

	As of January 31, 2021
	Fair Value		Level 1		Level 2		Level 3
	(in thousands)
Financial Assets:
Money market funds	$	958,357	$	958,357	$	—	$	—
Treasury bills	618,498		—		618,498		—
Cash equivalents	1,576,855		958,357		618,498		—
Commercial paper	26,222		—		26,222		—
Agency bonds	461,365		—		461,365		—
Corporate and other debt securities	466,256		—		466,256		—
U.S. government agency securities	834,665		—		834,665		—
Treasury bills	215,902		—		215,902		—
Marketable securities	2,004,410		—		2,004,410		—
Certificate of deposit included in prepaid expenses and other current assets	100		—		100		—
Certificates of deposit included in other assets, noncurrent	2,238		—		2,238		—
Convertible note included in other assets, noncurrent	5,130		—		—		5,130
Total financial assets	$	3,588,733	$	958,357	$	2,625,246	$	5,130

	As of January 31, 2020
	Fair Value		Level 1		Level 2		Level 3
	(in thousands)
Financial Assets:
Money market funds	$	96,486	$	96,486	$	—	$	—
Commercial paper	4,994		—		4,994		—
Agency bonds	9,999		—		9,999		—
Cash equivalents	111,479		96,486		14,993		—
Commercial paper	37,894		—		37,894		—
Agency bonds	141,163		—		141,163		—
Corporate and other debt securities	321,166		—		321,166		—
U.S. government agency securities	71,837		—		71,837		—
Marketable securities	572,060		—		572,060		—
Certificate of deposit included in prepaid expenses and other current assets	100		—		100		—
Certificates of deposit included in other assets, noncurrent	2,301		—		2,301		—
Total financial assets	$	685,940	$	96,486	$	589,454	$	—