Intangible Assets Acquired Through Business Combinations and Goodwill - Intangible Assets Acquired From Business Combinations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020	Jan. 31, 2021
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, gross, beginning balance			$ 6,860
Additions and retirements, net			6,473
Intangible assets, gross, ending balance	$ 13,333		13,333
Accumulated amortization, beginning balance			(2,746)
Expense and retirements, net			(1,115)
Accumulated amortization, ending balance	(3,861)		(3,861)
Intangible assets, net, beginning balance			4,114
Intangible assets, net, ending balance	9,472		$ 9,472
Weighted Average Remaining Useful Life (Years)			5 years 8 months 12 days
Amortization of intangible assets	508	$ 283	$ 1,100	$ 838
Customer contract assets	744		744		$ 477
Other assets
Finite-lived Intangible Assets [Roll Forward]
Customer contract assets	88		88		$ 42
Developed technology
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, gross, beginning balance			3,305
Additions and retirements, net			2,374
Intangible assets, gross, ending balance	5,679		5,679
Accumulated amortization, beginning balance			(1,427)
Expense and retirements, net			(624)
Accumulated amortization, ending balance	(2,051)		(2,051)
Intangible assets, net, beginning balance			1,878
Intangible assets, net, ending balance	3,628		$ 3,628
Weighted Average Remaining Useful Life (Years)			3 years 10 months 24 days
Customer relationships
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, gross, beginning balance			$ 3,510
Additions and retirements, net			3,799
Intangible assets, gross, ending balance	7,309		7,309
Accumulated amortization, beginning balance			(1,279)
Expense and retirements, net			(474)
Accumulated amortization, ending balance	(1,753)		(1,753)
Intangible assets, net, beginning balance			2,231
Intangible assets, net, ending balance	5,556		$ 5,556
Weighted Average Remaining Useful Life (Years)			6 years 10 months 24 days
Other purchased intangible assets
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, gross, beginning balance			$ 45
Additions and retirements, net			300
Intangible assets, gross, ending balance	345		345
Accumulated amortization, beginning balance			(40)
Expense and retirements, net			(17)
Accumulated amortization, ending balance	(57)		(57)
Intangible assets, net, beginning balance			5
Intangible assets, net, ending balance	$ 288		$ 288
Weighted Average Remaining Useful Life (Years)			5 years 8 months 12 days