Cash and Cash Equivalents, Investments, and Funds Held for Customers - Classified by the stated maturity date (Details) - USD ($) $ in Millions	Jan. 31, 2021	Jul. 31, 2020
Amortized Cost
Due within one year	$ 414	$ 389
Due within two years	284	256
Due within three years	277	137
Due after three years	6	18
Total available-for-sale debt securities	981	800
Fair Value
Due within one year	415	390
Due within two years	287	261
Due within three years	278	139
Due after three years	6	18
Total available-for-sale debt securities	986	808
Long-term investments	$ 41	$ 19