Short-Term Investments

3 Months Ended

Apr. 30, 2019

Investments Debt And Equity Securities [Abstract]

Short-Term Investments

Note 2. Short-Term Investments

At April 30, 2019, short-term investments consisted of the following (in thousands):

			Gross		Gross			Estimated
	Amortized		unrealized		unrealized			fair
	cost		gains		losses			value
Available-for-sale securities:
Certificates of deposits	$	3,500	$	11	$	—		$	3,511
Asset-backed securities		81,578		65		(138	)		81,505
Commercial paper		13,613		6		—			13,619
Corporate notes and bonds		226,957		526		(206	)		227,277
Foreign government bonds		1,501		—		(8	)		1,493
U.S. agency obligations		3,000		1		—			3,001
U.S. treasury securities		250,940		152		(8	)		251,084
Total available-for-sale securities	$	581,089	$	761	$	(360	)	$	581,490

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

			Gross		Gross			Estimated
	Amortized		unrealized		unrealized			fair
	cost		gains		losses			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):

	April 30,		January 31,
	2019		2019
Due in one year or less	$	371,297	$	377,858
Due in greater than one year		210,193		161,332
Total	$	581,490	$	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 April 30, 2019 and January 31, 2019.

The following table shows the fair values of these available-for-sale securities that have been in a gross unrealized loss position for more than 12 months, aggregated by investment category as of April 30, 2019 (in thousands):  

			Gross
	Fair		unrealized
	value		losses
Asset-backed securities	$	40,460	$	(138	)
Commercial paper		2,973		—
Corporate notes and bonds		53,533		(206	)
Foreign government bonds		1,494		(8	)
U.S. treasury securities		85,774		(8	)

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

			Gross
	Fair		unrealized
	value		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	)