Cash and Cash Equivalents, Investments, and Funds Held for Customers - Investments in funds receivable and amounts held for customers (Details) - USD ($) $ in Millions	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2019
Cash and Cash Equivalents, Investments and Funds Held for Customers [Abstract]
Restricted cash and restricted cash equivalents	$ 201	$ 257	$ 255	$ 236
Restricted available-for-sale debt securities and funds receivable	230	200	200	200
Total funds receivable and amounts held for customers	$ 431	$ 457	$ 455	$ 436

Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, 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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Name:	us-gaap_RestrictedCashAndCashEquivalents
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant