v3.26.1
Short-term Borrowings and Long-term Debt (Significant Long-term Debt Issued) (Details) - USD ($)
$ in Millions
 6 Months Ended
Jul. 31, 2026
Jul. 31, 2025
Debt Instrument [Line Items]    
Proceeds from issuance of long-term debt $ 4,230 $ 3,983
Senior Unsecured Notes    
Debt Instrument [Line Items]    
Proceeds from issuance of long-term debt 4,230  
Senior Unsecured Notes | Floating Debt, Due 2029    
Debt Instrument [Line Items]    
Principal Amount 350  
Proceeds from issuance of long-term debt 349  
Senior Unsecured Notes | 4.000% Debt, Due 2029    
Debt Instrument [Line Items]    
Principal Amount $ 650  
Interest Rate 4.00%  
Proceeds from issuance of long-term debt $ 648  
Senior Unsecured Notes | 4.150% Debt, Due 2031    
Debt Instrument [Line Items]    
Principal Amount $ 1,000  
Interest Rate 4.15%  
Proceeds from issuance of long-term debt $ 994  
Senior Unsecured Notes | 4.450% Debt, Due 2033    
Debt Instrument [Line Items]    
Principal Amount $ 1,250  
Interest Rate 4.45%  
Proceeds from issuance of long-term debt $ 1,244  
Senior Unsecured Notes | 4.750% Debt, Due 2036    
Debt Instrument [Line Items]    
Principal Amount $ 1,000  
Interest Rate 4.75%  
Proceeds from issuance of long-term debt $ 995