Fair Value Measurements (Fair Value Hierarchy) (Details) - Cash and Cash Equivalents - USD ($) $ in Millions	May 01, 2020	Jan. 31, 2020
Total cash equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	$ 5,137	$ 2,260
Total cash equivalents | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	5,109	2,158
Total cash equivalents | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	28	102
Money-market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	5,109	2,158
Money-market funds | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	5,109	2,158
Money-market funds | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0	0
Demand deposits and time deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	28	102
Demand deposits and time deposits | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0	0
Demand deposits and time deposits | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	$ 28	$ 102