Short-Term Investments

9 Months Ended

Oct. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Short-Term Investments

2. Short-Term Investments

At October 31, 2019, short-term investments consisted of the following (in thousands):

	Amortized cost		Gross unrealized gains		Gross unrealized losses			Estimated fair value
Available-for-sale securities:
Certificates of deposits	$	3,500	$	5	$	—		$	3,505
Asset-backed securities	84,092		262		(6		)	84,348
Commercial paper	24,604		4		(2		)	24,606
Corporate notes and bonds	218,314		1,437		(26		)	219,725
Foreign government bonds	1,500		—		—			1,500
U.S. agency obligations	3,000		—		—			3,000
U.S. treasury securities	265,123		616		(16		)	265,723
Total available-for-sale securities	$	600,133	$	2,324	$	(50	)	$	602,407

At January 31, 2019, short-term investments consisted of the following (in thousands):

	Amortized cost		Gross unrealized gains		Gross unrealized losses			Estimated fair value
Available-for-sale securities:
Certificates of deposits	$	6,001	$	10	$	(1	)	$	6,010
Asset-backed securities	78,682		13		(300		)	78,395
Commercial paper	9,118		1		(2		)	9,117
Corporate notes and bonds	185,409		178		(457		)	185,130
Foreign government bonds	1,502		—		(11		)	1,491
U.S. agency obligations	15,912		2		(2		)	15,912
U.S. treasury securities	243,119		78		(62		)	243,135
Total available-for-sale securities	$	539,743	$	282	$	(835	)	$	539,190

The following table summarizes the estimated fair value of our short-term investments, designated as available-for-sale and classified by the contractual maturity date of the securities as of the dates shown (in thousands):

	October 31, 2019		January 31, 2019
Due in one year or less	$	351,301	$	377,858
Due in greater than one year	251,106		161,332
Total	$	602,407	$	539,190

We have certain available-for-sale securities in a gross unrealized loss position, some of which have been in that position for more than 12 months. We review our debt securities classified as short-term investments on a regular basis to evaluate whether or not any security has experienced an other-than-temporary decline in fair value. We consider factors such as the length of time and extent to which the market value has been less than the cost, our financial position and near-term prospects and our intent to sell, or whether it is more likely than not we will be required to sell the investment before recovery of the investment’s amortized-cost basis. If we determine that an other-than-temporary decline exists in one of these securities, we would write down the respective investment to fair value. For debt securities, the portion of the write-down related to credit loss would be recognized as other income, net in our condensed consolidated statements of comprehensive income. Any portion not related to credit loss would be included in accumulated other comprehensive income. There were no impairments considered other-than-temporary as of October 31, 2019 and January 31, 2019.

The following table shows the fair values of these available-for-sale securities, some of which have been in a gross unrealized loss position for more than 12 months, aggregated by investment category as of October 31, 2019 (in thousands):

	Fair value		Gross unrealized losses
Asset-backed securities	$	9,545	$	(6	)
Commercial paper	10,561		(2		)
Corporate notes and bonds	27,851		(26		)
U.S. treasury securities	33,093		(16		)

The following table shows the fair values of these available-for-sale securities, some of which have been in a gross unrealized loss position for more than 12 months, aggregated by investment category as of January 31, 2019 (in thousands):

	Fair value		Gross unrealized losses
Certificates of deposits	$	999	$	(1	)
Asset-backed securities	69,131		(300		)
Commercial paper	7,155		(2		)
Corporate notes and bonds	121,006		(457		)
Foreign government bonds	1,490		(11		)
U.S. agency obligations	14,928		(2		)
U.S. treasury securities	130,785		(62		)