Leases and Other Commitments - Balance Sheet and Other Information Related to Leases (Details) $ in Millions	Jan. 31, 2020 USD ($)
Operating leases:
Operating lease right-of-use assets	$ 3,040
Operating lease liabilities, current	750
Noncurrent operating lease liabilities	2,445
Total operating lease liabilities	3,195
Finance leases:
Accumulated depreciation	(404)
Property and equipment, net	389
Accrued expenses and other liabilities	53
Other noncurrent liabilities	332
Total finance lease liabilities	$ 385
Weighted average remaining lease term
Operating leases	7 years
Finance leases	18 years
Weighted average discount rate
Operating leases	2.70%
Finance leases	4.50%
Buildings and building improvements
Finance leases:
Finance leases, gross	$ 325
Computers, equipment and software
Finance leases:
Finance leases, gross	$ 468