Fair Value of Financial Instruments (Tables)

3 Months Ended

Oct. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of Available-for-sale Securities Reconciliation

Available-for-sale investments within cash equivalents and investments consist of the following (in thousands):

	October 31, 2019
	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
U.S. Government agency securities	$	85,668	$	59	$	(7)	$	85,720
Commercial paper	165,218		—		—		165,218
Corporate bonds	651,550		2,528		(4)		654,074
U.S. Government bonds	148,035		279		(1)		148,313
Asset-backed securities	60,244		65		—		60,309
Foreign government bonds	14,975		—		—		14,975
Certificates of deposit	37,545		—		—		37,545
Money market funds	101,064		—		—		101,064
Total	$	1,264,299	$	2,931	$	(12)	$	1,267,218

	July 31, 2019
	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
U.S. Government agency securities	$	55,904	$	4	$	(29)	$	55,879
Commercial paper	239,333		—		—		239,333
Corporate bonds	666,087		1,612		(111)		667,588
U.S. Government bonds	130,530		94		(29)		130,595
Certificates of deposit	50,796		—		—		50,796
Money market funds	115,711		—		—		115,711
Total	$	1,258,361	$	1,710	$	(169)	$	1,259,902

Schedule of Unrealized Loss on Investments

The following table shows the gross unrealized losses and fair value of the Company’s investments with unrealized losses, aggregated by investment category and the length of time that individual securities have been in an unrealized loss position (in thousands):

	October 31, 2019
	Less Than 12 Months				12 Months or Greater				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
U.S. Government agency securities	$	17,993	$	(7)	$	—	$	—	$	17,993	$	(7)
Corporate bonds	14,480		(4)		—		—		14,480		(4)
U.S. Government bonds	2,645		(1)		—		—		2,645		(1)
Total	$	35,118	$	(12)	$	—	$	—	$	35,118	$	(12)

Investments Classified by Contractual Maturity Date

The following table summarizes the contractual maturities of the Company’s available-for-sale investments measured at fair value (in thousands):

	October 31, 2019
	Less Than 12 Months		12 Months or Greater		Total
U.S. Government agency securities	$	36,780	$	48,940	$	85,720
Commercial paper	165,218		—		165,218
Corporate bonds	460,386		193,688		654,074
U.S. Government bonds	130,612		17,701		148,313
Asset-backed securities	22,338		37,971		60,309
Foreign government bonds	14,975		—		14,975
Certificates of deposit	35,048		2,497		37,545
Money market funds	101,064		—		101,064
Total	$	966,421	$	300,797	$	1,267,218

Fair Value, Assets Measured on Recurring Basis

The following tables summarize the Company’s available-for-sale investments measured at fair value on a recurring basis, by level within the fair value hierarchy (in thousands):

	October 31, 2019
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Commercial paper	$	—	$	33,230	$	—	$	33,230
Money market funds	101,064		—		—		101,064
Total cash equivalents	101,064		33,230		—		134,294
Short-term investments:
U.S. Government agency securities	—		36,780		—		36,780
Commercial paper	—		131,988		—		131,988
Corporate bonds	—		460,386		—		460,386
U.S. Government bonds	—		130,612		—		130,612
Asset-backed securities	—		22,338		—		22,338
Foreign government bonds	—		14,975		—		14,975
Certificates of deposit	—		35,048		—		35,048
Total short-term investments	—		832,127		—		832,127
Long-term investments:
U.S. Government agency securities	—		48,940		—		48,940
Corporate bonds	—		193,688		—		193,688
U.S. Government bonds	—		17,701		—		17,701
Asset-backed securities	—		37,971		—		37,971
Certificates of deposit	—		2,497		—		2,497
Total long-term investments	—		300,797		—		300,797
Total	$	101,064	$	1,166,154	$	—	$	1,267,218

	July 31, 2019
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Commercial paper	$	—	$	56,132	$	—	$	56,132
Corporate bonds	—		4,398		—		4,398
Money market funds	115,712		—		—		115,712
Total cash equivalents	115,712		60,530		—		176,242
Short-term investments:
U.S. Government agency securities	—		39,166		—		39,166
Commercial paper	—		183,201		—		183,201
Corporate bonds	—		477,169		—		477,169
U.S. Government bonds	—		123,600		—		123,600
Certificates of deposit	—		47,000		—		47,000
Total short-term investments	—		870,136		—		870,136
Long-term investments:
U.S. Government agency securities	—		16,713		—		16,713
Corporate bonds	—		186,021		—		186,021
U.S. Government bonds	—		6,994		—		6,994
Certificates of deposit	—		3,796		—		3,796
Total long-term investment	—		213,524		—		213,524
Total	$	115,712	$	1,144,190	$	—	$	1,259,902