Goodwill and Acquired Intangible Assets - Intangible Assets Acquired (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Apr. 30, 2021	Jul. 31, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 4,166	$ 744
Accumulated amortization	(845)	(716)
Acquired intangible assets, net	$ 3,321	$ 28
Weighted average life in years	14 years	4 years
Customer Lists / User Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 3,038	$ 256
Accumulated amortization	(330)	(248)
Acquired intangible assets, net	$ 2,708	$ 8
Weighted average life in years	15 years	5 years
Purchased Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 686	$ 421
Accumulated amortization	(439)	(404)
Acquired intangible assets, net	$ 247	$ 17
Weighted average life in years	5 years	3 years
Trade Names and Logos
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 400	$ 25
Accumulated amortization	(35)	(25)
Acquired intangible assets, net	$ 365	$ 0
Weighted average life in years	15 years	0 years
Covenants Not to Compete or Sue
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 42	$ 42
Accumulated amortization	(41)	(39)
Acquired intangible assets, net	$ 1	$ 3
Weighted average life in years	3 years	3 years