Fair Value Measurements - Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Oct. 31, 2021	Jul. 31, 2021
Financial Assets:
Short-term investments:	$ 925,116	$ 928,006
Recurring
Financial Assets:
Total measured at fair value	1,042,420	1,032,588
Cash	233,681	181,141
Total cash, cash equivalents and short-term investments	1,276,101	1,213,729
Recurring \| Money market funds
Financial Assets:
Cash equivalents:	107,304	72,583
Recurring \| Commercial paper
Financial Assets:
Cash equivalents:	10,000	29,997
Short-term investments:	346,347	347,088
Recurring \| Corporate bonds
Financial Assets:
Cash equivalents:		2,002
Short-term investments:	517,494	513,688
Recurring \| U.S. government securities
Financial Assets:
Short-term investments:	61,275	67,230
Recurring \| Level I
Financial Assets:
Total measured at fair value	107,304	72,583
Recurring \| Level I \| Money market funds
Financial Assets:
Cash equivalents:	107,304	72,583
Recurring \| Level I \| Commercial paper
Financial Assets:
Cash equivalents:	0	0
Short-term investments:	0	0
Recurring \| Level I \| Corporate bonds
Financial Assets:
Cash equivalents:		0
Short-term investments:	0	0
Recurring \| Level I \| U.S. government securities
Financial Assets:
Short-term investments:	0	0
Recurring \| Level II
Financial Assets:
Total measured at fair value	935,116	960,005
Recurring \| Level II \| Money market funds
Financial Assets:
Cash equivalents:	0	0
Recurring \| Level II \| Commercial paper
Financial Assets:
Cash equivalents:	10,000	29,997
Short-term investments:	346,347	347,088
Recurring \| Level II \| Corporate bonds
Financial Assets:
Cash equivalents:		2,002
Short-term investments:	517,494	513,688
Recurring \| Level II \| U.S. government securities
Financial Assets:
Short-term investments:	61,275	67,230
Recurring \| Level III
Financial Assets:
Total measured at fair value	0	0
Recurring \| Level III \| Money market funds
Financial Assets:
Cash equivalents:	0	0
Recurring \| Level III \| Commercial paper
Financial Assets:
Cash equivalents:	0	0
Short-term investments:	0	0
Recurring \| Level III \| Corporate bonds
Financial Assets:
Cash equivalents:		0
Short-term investments:	0	0
Recurring \| Level III \| U.S. government securities
Financial Assets:
Short-term investments:	$ 0	$ 0

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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