Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	Apr. 30, 2019	Jul. 31, 2018	Apr. 30, 2018	Jul. 31, 2017
Statement of Cash Flows [Abstract]
Cash and cash equivalents	$ 2,946	$ 1,464	$ 1,614
Restricted cash and restricted cash equivalents included in funds held for customers	183	167	219	$ 172
Total cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period	$ 3,129	$ 1,631	$ 1,833	$ 701