Stockholders' Equity - Restricted Stock Unit Activity and Related Share-Based Compensation Expense (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Dec. 03, 2020	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2019
Summary of restricted stock unit activity
Nonvested, number of shares, beginning balance (in shares)		5,664,000	5,683,000	7,383,000
Equity instruments other than options, assumed in acquisition during period, number (in shares)		1,998,000
Granted (in shares)		3,877,000	2,657,000	2,452,000
Vested (in shares)		(2,242,000)	(2,039,000)	(3,123,000)
Forfeited (in shares)		(1,034,000)	(637,000)	(1,029,000)
Nonvested, number of shares, ending balance (in shares)		9,038,000	5,664,000	5,683,000
Weighted Average Grant Date Fair Value
Nonvested, weighted average grant date fair value per share, beginning balance (in dollars per share)		$ 231.97	$ 186.22	$ 131.50
Assumed through acquisition (in dollars per share)		355.49
Granted (in dollars per share)		431.82	271.80	245.40
Vested (in dollars per share)		262.23	180.40	129.31
Forfeited (in dollars per share)		251.41	154.91	107.40
Nonvested, weighted average grant date fair value per share, ending balance (in dollars per share)		$ 345.86	$ 231.97	$ 186.22
Total tax benefit related to RSU share-based compensation expense		$ 269	$ 173	$ 200
Restricted Stock Units (RSUs)
Summary of restricted stock unit activity
Restricted stock subject to revest provisions issued in connection with acquisition (in shares)		775,000
Weighted Average Grant Date Fair Value
Restricted stock subject to revest provisions issued in connection with acquisition (in dollars per share)		$ 355.49
Total fair market value of shares vested		$ 942	620	676
Share-based compensation for RSUs		708	382	351
Total tax benefit related to RSU share-based compensation expense		225	134	141
Cash tax benefits realized for tax deductions for RSUs		221	$ 139	$ 150
Unrecognized compensation cost		$ 2,800
Weighted average vesting period		3 years
Restricted Stock Units (RSUs) | Credit Karma
Summary of restricted stock unit activity
Equity instruments other than options, assumed in acquisition during period, number (in shares)	1,997,881
Granted (in shares)		809,000
Weighted Average Grant Date Fair Value
Fair value of equity awards		$ 300