Goodwill and Acquired Intangible Assets - Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2019
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,654	$ 1,655
Goodwill Acquired	3,957	0
Foreign Currency Translation	2	(1)
Goodwill, ending balance	5,613	1,654
Small Business & Self-Employed
Goodwill [Roll Forward]
Goodwill, beginning balance	1,518	1,518
Goodwill Acquired	59	0
Foreign Currency Translation	1	0
Goodwill, ending balance	1,578	1,518
Goodwill net of accumulated impairment losses			$ 114
Consumer
Goodwill [Roll Forward]
Goodwill, beginning balance	42	42
Goodwill Acquired	0	0
Foreign Currency Translation	0	0
Goodwill, ending balance	42	42
ProConnect
Goodwill [Roll Forward]
Goodwill, beginning balance	94	95
Goodwill Acquired	0	0
Foreign Currency Translation	1	(1)
Goodwill, ending balance	95	94
Credit Karma
Goodwill [Roll Forward]
Goodwill, beginning balance	0	0
Goodwill Acquired	3,898	0
Foreign Currency Translation	0	0
Goodwill, ending balance	$ 3,898	$ 0