Cash and Cash Equivalents, Investments, and Funds Receivable and Amounts Held for Customers - Type of Issue (Details) - USD ($)	Apr. 30, 2023	Jul. 31, 2022	Apr. 30, 2022	Jul. 31, 2021
Cash and Cash Equivalents Items [Line Items]
Total cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period	$ 3,750,000,000	$ 2,997,000,000	$ 3,870,000,000	$ 2,819,000,000
Available-for-sale securities:
Available-for-sale debt securities, amortized cost	729,000,000	694,000,000
Available-for-sale debt securities, fair value	723,000,000	685,000,000
Total cash, cash equivalents, restricted cash, restricted cash equivalents, and investments, amortized cost	4,479,000,000	3,691,000,000
Total cash, cash equivalents, restricted cash, restricted cash equivalents, and investments, fair value	4,473,000,000	3,682,000,000
Credit losses related to available-for-sale securities	0
Total cash, cash equivalents, restricted cash, and restricted cash equivalents
Cash and Cash Equivalents Items [Line Items]
Total cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period	3,750,000,000	2,997,000,000
Cash, cash equivalents, restricted cash, and restricted cash equivalents, fair value	3,750,000,000	2,997,000,000
Corporate notes
Available-for-sale securities:
Available-for-sale debt securities, amortized cost	596,000,000	597,000,000
Available-for-sale debt securities, fair value	591,000,000	589,000,000
U.S. agency securities
Available-for-sale securities:
Available-for-sale debt securities, amortized cost	133,000,000	97,000,000
Available-for-sale debt securities, fair value	$ 132,000,000	$ 96,000,000