Fair Value of Financial Instruments (Tables)

9 Months Ended

Apr. 30, 2020

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):

	April 30, 2020
	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
U.S. Government agency securities	$	133,556	$	171	$	(107)	$	133,620
Commercial paper	156,729		—		—		156,729
Corporate bonds	609,810		2,800		(561)		612,049
U.S. Government bonds	78,138		733		—		78,871
Asset-backed securities	60,450		292		(18)		60,724
Foreign government bonds	10,867		4		(1)		10,870
Certificates of deposit	37,645		—		—		37,645
Money market funds	182,258		—		—		182,258
Total	$	1,269,453	$	4,000	$	(687)	$	1,272,766

	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):

	April 30, 2020
	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	$	61,828	$	(107)	$	—	$	—	$	61,828	$	(107)
Corporate bonds	80,295		(561)		—		—		80,295		(561)
Asset-backed securities	1,478		(18)		—		—		1,478		(18)
Foreign government bonds	4,866		(1)		—		—		4,866		(1)
Total	$	148,467	$	(687)	$	—	$	—	$	148,467	$	(687)

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):

	April 30, 2020
	Less Than 12 Months		12 Months or Greater		Total
U.S. Government agency securities	$	20,742	$	112,878	$	133,620
Commercial paper	156,729		—		156,729
Corporate bonds	495,082		116,967		612,049
U.S. Government bonds	55,806		23,065		78,871
Asset-backed securities	26,121		34,603		60,724
Foreign government bonds	10,870		—		10,870
Certificates of deposit	33,398		4,247		37,645
Money market funds	182,258		—		182,258
Total	$	981,006	$	291,760	$	1,272,766

Fair Value, Assets Measured on Recurring Basis

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

	April 30, 2020
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Commercial paper	$	—	$	55,084	$	—	$	55,084
Corporate bonds	—		3,278		—		3,278
Money market funds	182,258		—		—		182,258
Total cash equivalents	182,258		58,362		—		240,620
Short-term investments:
U.S. Government agency securities	—		20,742		—		20,742
Commercial paper	—		101,645		—		101,645
Corporate bonds	—		491,804		—		491,804
U.S. Government bonds	—		55,806		—		55,806
Asset-backed securities	—		26,121		—		26,121
Foreign government bonds	—		10,870		—		10,870
Certificates of deposit	—		33,398		—		33,398
Total short-term investments	—		740,386		—		740,386
Long-term investments:
U.S. Government agency securities	—		112,878		—		112,878
Corporate bonds	—		116,967		—		116,967
U.S. Government bonds	—		23,065		—		23,065
Asset-backed securities	—		34,603		—		34,603
Certificates of deposit	—		4,247		—		4,247
Total long-term investments	—		291,760		—		291,760
Total	$	182,258	$	1,090,508	$	—	$	1,272,766

	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