Cash Equivalents and Short-term Investments (Tables)

3 Months Ended

Apr. 30, 2020

Investments, Debt and Equity Securities [Abstract]

Schedule of Amortized Costs, Unrealized Gains and Losses and Estimated Fair Value of Cash Equivalents and Short-term Investments

The amortized cost, unrealized gain (loss) and estimated fair value of the Company’s cash equivalents and short-term investments as of April 30, 2020 and January 31, 2020 were as follows (in thousands):  

	As of April 30, 2020
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(unaudited)
Cash equivalents:
Money market funds	$	497,208	$	—	$	—		$	497,208
Corporate debt securities	6,001		5		—			6,006
Total cash equivalents	503,209		5		—			503,214
Short-term investments:
U.S. treasury securities	575,143		4,935		(1		)	580,077
Corporate debt securities	246,587		1,029		(137		)	247,479
Total short-term investments	821,730		5,964		(138		)	827,556
Total	$	1,324,939	$	5,969	$	(138	)	$	1,330,770

	As of January 31, 2020
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	416,584	$	—	$	—		$	416,584
U.S. treasury securities	19,996		—		—			19,996
Total cash equivalents	436,580		—		—			436,580
Short-term investments:
U.S. treasury securities	575,920		686		(8		)	576,598
Corporate debt securities	305,859		519		—			306,378
Total short-term investments	881,779		1,205		(8		)	882,976
Total	$	1,318,359	$	1,205	$	(8	)	$	1,319,556

Schedule of Contractual Maturities of Short-term Investments

The following table presents the contractual maturities of the Company’s short-term investments as of April 30, 2020 (in thousands):

	As of April 30, 2020
	Amortized Cost		Estimated Fair Value
	(unaudited)
Due within one year	$	634,510	$	638,854
Due between one to five years	187,220		188,702
Total	$	821,730	$	827,556