Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Apr. 30, 2026	Jul. 31, 2025
Assets:
Cash equivalents, primarily money market funds	$ 4,681	$ 2,884
Total available-for-sale debt securities	2,249	1,818
Fair value, measurements, recurring
Assets:
Cash equivalents, primarily money market funds	1,852	1,790
Total available-for-sale debt securities	2,249	1,818
Total assets measured at fair value on a recurring basis	4,101	3,608
Fair value, measurements, recurring \| Level 1
Assets:
Cash equivalents, primarily money market funds	1,852	1,790
Total available-for-sale debt securities	0	0
Total assets measured at fair value on a recurring basis	1,852	1,790
Fair value, measurements, recurring \| Level 2
Assets:
Cash equivalents, primarily money market funds	0	0
Total available-for-sale debt securities	2,249	1,818
Total assets measured at fair value on a recurring basis	2,249	1,818
Fair value, measurements, recurring \| Corporate notes
Assets:
Total available-for-sale debt securities	607	502
Fair value, measurements, recurring \| Corporate notes \| Level 1
Assets:
Total available-for-sale debt securities	0	0
Fair value, measurements, recurring \| Corporate notes \| Level 2
Assets:
Total available-for-sale debt securities	607	502
Fair value, measurements, recurring \| U.S. agency securities
Assets:
Total available-for-sale debt securities	1,642	1,316
Fair value, measurements, recurring \| U.S. agency securities \| Level 1
Assets:
Total available-for-sale debt securities	0	0
Fair value, measurements, recurring \| U.S. agency securities \| Level 2
Assets:
Total available-for-sale debt securities	$ 1,642	$ 1,316