Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Oct. 31, 2025	Jul. 31, 2025
Assets:
Cash equivalents, primarily money market funds	$ 3,506	$ 2,884
Available-for-sale debt securities, fair value	340	1,818
Fair value, measurements, recurring
Assets:
Cash equivalents, primarily money market funds	2,330	1,790
Available-for-sale debt securities, fair value	340	1,818
Total assets measured at fair value on a recurring basis	2,670	3,608
Fair value, measurements, recurring | Level 1
Assets:
Cash equivalents, primarily money market funds	2,330	1,790
Available-for-sale debt securities, fair value	0	0
Total assets measured at fair value on a recurring basis	2,330	1,790
Fair value, measurements, recurring | Level 2
Assets:
Cash equivalents, primarily money market funds	0	0
Available-for-sale debt securities, fair value	340	1,818
Total assets measured at fair value on a recurring basis	340	1,818
Fair value, measurements, recurring | Corporate notes
Assets:
Available-for-sale debt securities, fair value	335	502
Fair value, measurements, recurring | Corporate notes | Level 1
Assets:
Available-for-sale debt securities, fair value	0	0
Fair value, measurements, recurring | Corporate notes | Level 2
Assets:
Available-for-sale debt securities, fair value	335	502
Fair value, measurements, recurring | U.S. agency securities
Assets:
Available-for-sale debt securities, fair value	5	1,316
Fair value, measurements, recurring | U.S. agency securities | Level 1
Assets:
Available-for-sale debt securities, fair value	0	0
Fair value, measurements, recurring | U.S. agency securities | Level 2
Assets:
Available-for-sale debt securities, fair value	$ 5	$ 1,316