Leases (Schedule of Other Information Relating to Lease Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2021
Leases [Abstract]
Operating cash flows from operating leases	$ 2,280	$ 2,234	$ 2,629
Operating cash flows from finance leases	248	225	286
Financing cash flows from finance leases	563	538	546
Assets obtained in exchange for operating lease obligations	1,714	1,816	2,131
Assets obtained in exchange for finance lease obligations	$ 1,226	$ 1,044	$ 1,547
Weighted-average remaining lease term - operating leases	12 years	12 years 2 months 12 days
Weighted-average remaining lease term - finance leases	13 years 3 months 18 days	13 years 4 months 24 days
Weighted-average discount rate - operating leases	6.00%	5.90%
Weighted-average discount rate - finance leases	6.50%	6.50%